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TRANSCRIPT
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DEPARTMENT OF THE ARMY FIELD MANUAl
105-mmHOWITZER
M2A1 ON MOTORCARRIAGE
M7B1 AND M7B2
DEPARTMENT OF THE ARMY MARCH 1954
AGO 4416C-Mar
* FM 6-74
FIELD MANUAL t DEPARTMENT OF THE ARMYNo. 6-74 S WASHINGTON 25, D. C., 12 March 1954
105-MM HOWITZER M2A1 ON MOTOR CARRIAGE
M7B1 AND M7B2
Paragraphs Page
CHAPTER 1. INTRODUCTION_----------. 1-4 3
2. ORGANIZATION__---------. 5, 6 7
3. SECTION DRILLSection I. General ______-___-----_---- 7, 8 9
II. Preliminary commands and 9-14 10formations.
CHAPTER 4. PREPARING THE GUNFOR FIRING ANDTRAVELING
Section I. Preparations for firing ______. 15,16 16II. Preparations for traveling____ 17, 18 18
CHAPTER 5. DUTIES IN FIRING
Section I. Indirect laying -------------- 19-28 19II. Direct laying, general________. 29-32 56
III. Direct laying, two-man, two- 33-37 65sight system.
IV. Direct laying, one-man, one- 38-41 72sight system.
* This manual supersedes FM 6-74, 10 July 1944, includig C 1, 9November 1944, TC 2, 19 January 1951, and TC 12, 12 March 1952.
AGO 4316C 1
Paragraphs Page
CHAPTER 6. TECHNIQUES AND SITUA- 42-52 75TIONS THAT REQUIRESPECIAL ATTENTION.
7. BORE SIGHTING ANDBASIC PERIODIC TESTS
Section I. General ____________________ 53; 54 88II. Bore sighting__--__._________ 55-60 90
III. Basic periodic tests ---------_ 61-65 111
CHAPTER 8. MAINTENANCE AND IN- 66-75 122SPECTIONS.
9. DECONTAMINATION OF 76-79 143EQUIPMENT.
10. DESTRUCTION OF EQUIP- 80-82 1A6MENT.
11. SAFETY PRECAUTIONS___ 83-86 148
12. TRAININGSection I. General__-__________________ 87-90 151
II. Tests for qualification of gun- 91-104 153ners.
APPENDIX REFERENCES _____________- ______ 182
INDEX _________________________________- ______ 185
2 AGO 4316C
CHAPTER 1
INTRODUCTION
1. Purpose and Scope
This manual is a guide to assist commanders indeveloping the sections of 105-mm howitzer motorcarriage M7B1 and M7B2 firing batteries intoefficient smooth-working teams that have a senseof discipline which will impel them to operateeffectively under the stress of battle. This manualprescribes individual duties and section drills, in-spection and maintenance drills, tests and adjust-ments for sighting and fire control equipment,and references to instructions for the decontami-nation and destruction of equipment.
2. Definitions and Terms
a. Gun. Throughout this manual the term gunis used generally to include howitzer.
b. Section. Tables of organization and equip-ment prescribe the personnel and equipment com-prising each section of a battery (figs. 1 and 2).In this manual the term section is often used todesignate only the personnel required to serve onegun and its equipment.
c. Front. The front of a section is the directionin which the muzzle of the gun points.
AGO 4316C 3
Figure 1. 105-mm howitzer motor carriage M7B1 (M7B2)and section personnel.
d. Right (Left). The direction right (left) isthe right (left)" of one facing the front.
e. In Battery. A gun is said to be in batterywhen it is in its normal firing position.
3. Description of Equipment
To avo'd accidents caused by exceeding thecapabilities and limitations of the motor carriage,
4 AGO 4316C
Figure 2. A method of displaying section equipment of the105-mm howitzer motor carriage M7B1 and M7B2.
all members of the section should be familiar withthe performance characteristics shown in figure3. For further details pertaining to full-trackvehicle capabilities and combat driving, see TM21-306.
4. References
Publications pertaining to the 105-mm howitzerM2A1 on motor carriage M7B1 and M7B2 andauxiliary equipment, covering related matters notdiscussed in detail in this manual, are listed in theappendix.
AGO 4816C 5
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6 AGO '416d
CHAPTER 2
ORGANIZATION
5. Composition of the Gun Section
a. The gun section consists of section personnel,a 105-mm howitzer M2A1 (or M2) mounted onmotor carriage M7B1 (or M7B2), and auxiliaryequipment (fig. 1).
b. The personnel of the gun section are-(1) A chief of section (CS).(2) A gunner (G).(3) An assistant gunner (No. 1).(4) Four cannoneers, numbered from 2
through 5.(5) A motor carriage driver (D).
c. Section equipment is listed in SNL's (app.)and the T/O&E appropriate to the weapon andunit.
6. General Duties of Personnel
a. Chief of Section. The chief of section is thenoncommissioned officer in command of the sec-tion and, as such, is responsible to the batteryexecutive for-
(1) Training and efficiency of personnel.(2) Performance of duties listed under sec-
tion drill, duties in firing, testing and
AGO 4816C 7
adjustment of sighting and fire controlequipment, and inspection and mainte-nance of all section equipment includingscheduled preventive maintenance onmotor carriage.
(3) Observance of safety precautions.(4) Preparation of field fortifications for
protection of equipment, ammunition,and personnel.
(5) Camouflage discipline; local security;and radiological, biological, and chemi-cal security discipline.
(6) Maintenance of the gun book.(7) Police of the section area.
b. Gunner. The gunner is the assistant to thesection chief in.carrying out the duties specifiedin a above. The gunner's specific duties are pre-scribed in the appropriate chapters of this manual.
c. Cannoneers. Cannoneers perform duties aslisted in this manual and any other duties thatthe chief of section prescribes.
d. Driver. The driver's primary duty is drivingthe motor carriage (TM 21-306). He also per-forms maintenance and such other duties as pre-scribed by this manual, by TM 9-749, or as maybe assigned by the chief of section. These dutiescan include substituting for any member of thesection in firing.
8 AGO 4316C
CHAPTER 3
SECTION DRILL
Section I. GENERAL
7. Objective
The objective of section drill is the attainmentof efficiency: Maximum precision coupled withhigh speed.
8. Instructions
a. To develop maximum efficiency and to pre-vent injuries to personnel and equipment, thedrills prescribed in this manual must be observed.Section drill should be conducted in silence exceptfor commands and reports. The section must bedrilled until reactions to commands are auto-matic, rapid, and efficient.
b. Mistakes are corrected immediately. Eachmember of the section must be impressed with theimportance of reporting promptly to the chief ofsection any mistakes discovered after the com-mand to fire has been given. The chief of sectionwill report mistakes immediately to the executive.
c. Battery officers supervise the drill to insurethat instructions are carried out and that maxi-mum efficiency is obtained.
d. Duties should be rotated -during training sothat each member of the section can perform all
AGO 4816C 9
the duties within the section. In addition, batteryoverhead personnel not assigned specific dutiesduring drill periods should be trained in thefundamentals of section drill in order that theywill be capable of functioning efficiently with agun section if required.
Section II. PRELIMINARY COMMANDS AND FORMATIONS
9. To Form the Section
a. To Fall In. The chief of section takes hispost. On the command of execution the sectionforms in a single rank at close interval, centeredon and facing the chief of section at a distanceof 3 paces (fig. 4). Higher numbered cannoneers,if present, form in order between No. 5 and thedriver. The chief of section may indicate in hispreparatory command the place and direction thesection is to form. At the first formation for adrill or exercise the caution, AS GUN SEC-TION (S), precedes the command. The commandsare FALL IN, or 1. IN FRONT (REAR) OF YOURGUN (S), 2. FALL IN, or 1. ON THE ROAD FACINGTHE PARK. 2. FALL IN. Execution is as follows:The section moves at double time and forms atclose interval, at attention, guiding on the gunner(fig. 4).
b. To Call Off. The section being in formation,the command is CALL OFF. At the command,all personnel in ranks, except the gunner, executeeyes right. The section then calls off in sequence,"Gunner," "1," "2," "3," "4," "5," "Driver." As
o10 AGO 48160
a.:..
Figure 4. Gun section in formation.
each man calls out his designation he turns hishead and eyes smartly to the front.
10. Posts of the Section
The command is 1. CANNONEERS, 2. POSTS.The command is general and is applicable whetherthe section is in or out of ranks, at a halt ormarching. All movements are executed at doubletime and are terminated at the position of atten-tion. Higher numbered cannoneers, if present,take posts as prescribed by the chief of section.
a. Dismounted. The section moves to posts asshown in figure 5. All personnel are 2 feet outsidethe tracks and facing to the front.
AGO 48160 11
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Figure 5. Posts of section, dismounted.
b. Prepared for Action. The gun hav'ng beenprepared for action, posts are taken as shown infigure 6.
c. Mounted, Not Prepared for Action. The scc-tion moves to posts as shown 'n figure 7.
11. To Change Posts
To acquaint the members of the section with allduties and to lend variety to drill, posts shouldbe changed frequently. The section being in for-mation the commands are 1. CHANGE POSTS, 2.MARCH, or 1. SECTION CHANGE POSTS, 2. MARCH.
a. At 1. CHANGE POSTS, 2. MARCH, all num-bered cannoneers except No. 5 (or the highest
12 AGO 4316C
1, 5)
Figure 6. Posts of section, prepared for action.
numbered cannoneer) take two left steps, takingthe position of the next higher numbered can-noneer. No. 5 moves at double time in rear of thesection to the post of No. 1. All ,other membersof the section stand fast.
b. At 1. SECTION CHANGE POSTS, 2. MARCH,the driver (or the leftmost man) moves at doubletime in rear of the section to the post of thegunner. The gunner and all other men in line taketwo left steps as in a above.
12. To Mount
The commands are 1. PREPARE TO MOUNT, 2.MOUNT, or 1. MOUNT.
AGO 4316C 13
Figure 7. Section mounted.
a. At the preparatory command, the sectionmoves at double time to positions shown in figure5. At the command of execution, all personnel'mount. On the right Nos. 2 and 4 mount first,,followed by Nos. 1 and 5 respectively. On the leftthe driver and No. 3 mount first, followed by the.chief of section and the gunner respectively. All:personnel hasten to positions as shown in figure 7.
b. If any members of the section are to remain:dismounted, their designation is announced with.the caution, STAND FAST given between thepreparatory command and the command of exe-cution. For example: 1. PREPARE TO MOUNT,.
DRIVER STAND FAST, 2. MOUNT.
14 AGO 4316C:
c. If the command is 1. MOUNT, the sectionexecutes, without pausing, all that has been pre-scribed for the command 1. PREPARE TO MOUNT,
2. MOUNT.
13. To DismountThe commands are 1. PREPARE TO DISMOUNT,
2. DISMOUNT, or 1. DISMOUNT.a. At the preparatory command all members
of the section stand. At the command of execu-tion members of the section dismount in inverseorder of mounting and quickly take posts as shownin figure 5.
b. If the command is 1. DISMOUNT, the sec-tion executes without pausing all that has beenprescribed for the command 1. PREPARE TO DIS-
MOUNT, 2. DISMOUNT.
14. To Fall Outa. At Drill. When it is desired to give the per-
sonnel a rest from drill or relieve them tempo-rarily from a formation or post, the commandFALL OUT is given. The command may be givenat any time and means that the section is to re-main in the vicinity of the drill area.
b. When Firing. When firing has been sus-pended temporarily, but it is desired to have thesection remain in the vicinity of the motor car-riage, the command FALL OUT is given. Menstand clear of the gun to insure that settings andlaying remain undisturbed. During these periodsthe chief of section may direct his men to improvethe position, to replenish ammunition, or to doother necessary work.
AGO 4316C 15
CHAPTER 4
PREPARING THE GUN FOR FIRING ANDTRAVELING
Section I. PREPARATIONS FOR FIRING
15. General
The guns of a battery will ordinarily be putinto position individually under the direction ofthe executive and chiefs of section. A stake shouldbe driven into the ground at a point where thecenter of each carriage is to be placed. Anotherstake should be placed in the direction of fire 50to 100 yards from the first stake, so that the driverof the motor carriage can point the tube at thefar stake as he drives the vehicle into positionover the first stake. Each vehicle is halted at itsproper place by the chief of section. Hand signalsfor guiding the vehicle are found in FM 21-60,FM 25-10, and are discussed in paragraph 51.
16. To Prepare for Action
a. The gun being in position or approaching it,the command is PREPARE FOR ACTION. Dutiesof individuals are given in table I. Each mantakes his post (fig. 6) upon completion of hisduties.
16 AGO 4316C
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b. The gun normally wilLbhe.partially preparedfor action before reaching the firing position. Theduties of the cannoneers in preparing for actionare the same whether moving or halted; but onlysuch operations as are practicable are carried outwhile moving. Immediately after the gun is es-tablished in position, preparation for action iscompleted without further command.,
c. If PREPARE FOR ACTION has not been or-dered before the gun is established in position,the command is habitually given by the chief ofsection as soon as the vehicle is halted in position.If this is not desired, the caution DO NOT PRE-PARE FOR ACTION must be given.
Figure 8. Nos. 2 and 3 removing traveling lock bracket.
AGO U160 17
Section II. PREPARATIONS FOR TRAVELING
17. March Order
To prepare to resume travel the command isMARCH ORDER. Duties of individuals are listedin table II. Each man takes his post (fig. 7) uponcompletion of his duties.
18. To Resume Firing in Another Position
a. If firing is to be resumed shortly in anotherposition in which the gun must be immediatelyready to fire, the command MARCH ORDER isnot given. When a displacement is ordered, onlythose operations necessary for the movement ofthe motor carriage and the security of equipmentare performed.
b. If the command MARCH ORDER is givenwhile the equipment is partially prepared fortravel as described in a above, the remainingoperations pertaining to march order are com-pleted.
18 AGO 4316C
CHAPTER 5
DUTIES IN FIRING
Section I. INDIRECT LAYING
19. Instructions
The general instructions given in paragraphs7 and 8 on the conduct of section drill applyequally to section drill in duties in firing. Forduties of the battery executive see FM 6-140.
20. Duties of Individuals
In general, the duties of individuals in the sec-tion in firing are as follows:
a. The chief of section supervises and com-mands his section and is responsible that all dutiesof the section are performed properly, all com-mands executed, and all safety precautions ob-served.
b. The gunner sets the announced deflection,lays for direction, and refers the gun.
c. No. 1 sets the announced site and elevation,lays for elevation, operates the breech, and firesthe gun.
d. No. 2 loads the gun.
e. No. 3 operates the fuze setter and sets thefuzes.
AGO 4316C 19
f. No. 4 prepares charges.
g. No. 5 removes ammunition from containers.
h. The driver remains at his post, prepared tomove the carriage if large shifts are expected.When direction of fire is relatively stable, heperforms such maintenance on the vehicle as willnot interfere.with firing unless assigned otherduties by the chief of section.
21. Chief of Section
a. List of Duties.
(1) To lay for elevation, assisted by No. 1,when the gunner's quadrant is used.,
(2) To measure the elevation.(3) To measure the site to the mask.(4) To indicate to the gunner the aiming
point.(5) To follow fire commands.(6) To indicate when the gun is ready to fire.(7) To give the command to fire.(8) To report mistakes and other unusual
incidents of fire to the executive.(9) To conduct prearranged fires.
(10) To record basic data.(11) To observe and check frequently the
functioning of the materiel.(12) To assign duties when firing with re-
duced personnel.(13) To verify the adjustment of the sighting
and fire control equipment.
20 AGO 4316C
(14) To check, before they are replaced intheir containers, all rounds not firedwhich have been prepared for firing.
(15) To control the movement of the motorcarriage.
(16) To supervise use of ammunition.b. Detailed Description of Duties.
(1) To lay for elevation when gunner's quad-rant is used.
(a) The command QUADRANT (SOMUCH) indicates that the gunner'squadrant is to be used. In laying forelevation, it is usually employed onlywhen the elevation (range) quadrantis inoperative or known to be inac-curate. The gunner's quadrant may bespecified for use with assault fire oron certain destruction missions.
(b) Quadrant 361.8, for example, is set onthe gunner's quadrant (fig. 9) as fol-lows: The upper edge of the indexplate is set opposite the 360 mark ofthe graduated arch on the quadrantframe and the micrometer on the indexarm is turned to read 1.8. Care mustbe taken to use the same side of thequadrant in setting both the indexplate and the micrometer knob.
(c) The announced quadrant having beenset on the gunner's quadrant, the gunloaded, and the breechblock closed,the gunner's quadrant is set on the
AGO 4316C 21
Figure 9. Setting the gunner's quadrant at 361.8.
quadrant seat on top of the breech.The words line of fire must be at thebottom of the quadrant and the arrowpointing toward the muzzle. The chiefof section must be sure to use the ar-row which appears on the same sideof the quadrant as the scale which heis using. He stands squarely oppositethe side of the quadrant and holds itfirmly; on the quadrant seat, parallelto the axis of the bore. It is importantthat he take the same position andhold the quadrant in the same mannerfor each subsequent setting, so that in
22 AGO 4816C
each case he will view the quadrantbubble from the same angle.
(d) The chief of section then directs No. 1to elevate or depress the tube untilthe bubble is centered, being carefulthat the last motion is in the directionin which it is more difficult to turnthe handwheel. The chief of sectioncautions No. 1 when the bubble is ap-proaching the center, in order thatthe final centering may be performedaccurately.
(e) Normally, special and calibration cor-rections will be added algebraically atthe battery fire direction center andcommanded as NO. (SO-AND-SO),QUADRANT (SO MUCH).
(2) To measure the elevation. At the com-mand MEASURE THE ELEVATION,the gun having been laid, the chief ofsection directs No. 1 to center the cross-level bubble, to set the angle of site at300, and with the elevation knob tocenter the elevation (range) quadrantlongitudinal-level bubble. The chief ofsection then reads the elevation set onthe elevation scale and micrometer andannounces the elevation thus set as "No.(so-and-so), elevation (so much)." If
the elevation quadrant is inoperative orknown to be inaccurate, the elevation ismeasured by placing the gunner's quad-
AGO 4816C 23
rant on the quadrant seats of the breechring where the chief of section, by rais-ing and lowering the index arm andturning the micrometer knob, centersthe bubble. He then reports the readingon the gunner's quadrant to the execu-tive.
(3) To measure site to the mask.
(a) The command is MEASURE THESITE TO THE MASK. The chief ofsection has No. 1 set site 300 on theangle of site scale and center the cross-level bubble. Then, sighting along thelowest element of the bore, he directsthe gunner and No. 1 to operate thetraversing and elevating mechanismuntil the line of sight just clears thecrest at its highest point in the prob-able field of fire. He then directs No. 1to center the longitudinal-level bubbleby turning the elevation knob. No. 1verifies that the cross-level bubble isstill centered. The chief of sectionreads the site to the mask from theelevation scale and micrometer andreports to the executive, "No. (so-and-so), site (so much)."
(b) When the executive announces theminimum quadrant elevation or theminimum elevation and site for eachcharge, the chief of section records itin a notebook and directs No. 1 to
24 AGO 4316C
chalk on a convenient place the mini-mum quadrant elevation for eachcharge to be used.
(4) To indicate to the gunner the aimingpoint. Whenever an aiming point has'been designated by the executive, thechief of section will make sure that hehas properly identified the point in ques-tion. He will then indicate it to thegunner. If there is any possibility ofmisunderstanding, the chief of sectionwill turn the panoramic telescope untilthe horizontal and vertical hairs are onthe point designated.
(5) To follow fire commands. The chief ofsection will follow fire commands. Hewill repeat the commands as required.
(6) To indicate when the gun is ready to fire.When the executive can see arm signalsof the chief of section, the chief of sec-tion will extend his right arm verticallyupward as a signal that the gun is readyto fire. He gives the signal as soon asthe gunner calls "Ready." When armsignals cannot be seen, the chief of sec-tion reports orally to the executive. "No.(so-and-so) ready."
(7) To give the command to fire. When No. 1can see arm signals made by the chiefof section, the chief of section will givethe command to fire by dropping hisright arm sharply to his side. When his
AGO 4316C 25
arm signals cannot be seen he commandsorally, FIRE or NO. (SO-AND-SO)FIRE. The chief of section will not givethe signal or command to fire until allcannoneers are in their proper places.
(8) To report mistakes and other unusualincidents of fire to the executive. If forany reason the gun cannot be fired, thechief of section will promptly reportthat fact to the executive and the reasonstherefor; for example, "No. (so-and-so)out, misfire." Whenever it is discoveredthat the gun has been fired with a mis-take in laying, the chief of section willreport that fact at once; for example,"No. (so-and-so) fired 40 mils right."Whenever the gunner reports that theaiming posts are out of alinement withthe sight and that the misalinement isdue to the displacement of the carriage,the chief of section will report that factand request permission to realine them.Likewise, he promptly reports other un-usual incidents that affect the service ofthe gun.
(9) To conduct prearranged fires. Wheneverthe execution of prearranged fires isordered, the chief of section will conductthe fire of his section in conformity withthe prescribed data.
(10) To record basic data. The chief of sectionwill record data of a semipermanent
26 AGO 48160C
nature in a notebook. This includes suchinformation as minimum elevations;aiming points used and their deflections;prearranged fires when section datasheets are not furnished; safety limitsin elevation and deflection; number ofrounds fired, with the date and hour;and calibration and special correctionswhen appropriate.
(11) To observe and check functioning of themateriel. The chief of section closelyobserves the functioning of all parts ofthe materiel during firing. Before thegun is fired, he makes sure that therecoil mechanism contains the properamount of oil; thereafter he carefullyobserves the functioning of the recoilsystem. He promptly reports to the exe-cutive any evidence of malfunctioning(TM 9-325). If the gun returns to bat-tery with a shock, an' over supply ofrecoil oil is indicated; if the gun overrecoils or does not return to battery, aninsufficient amount of recoil oil is in-dicated. Correct recoil oil pressureexists when the end of the oil index in-dicator rod is flush with the front faceof the recuperator cylinder front head.Whenever the amount of reserve oil isless than that prescribed, the indexindicator rod recedes into the oil indexrecess. If the oil reserve pressure is ex-
AGO 4816C 27
cessive, the oil index is mechanicallyunable to indicate this excess conditiondue to the construction of the mechanismindicator. This condition necessitatesextreme care in establishing the correctoil reserve.
(12) To assign duties when firing with reducedpersonnel. Whenever the personnel serv-ing the gun is temporarily reduced innumbers below that indicated in thismanual, the chief of section will makesuch redistribution of duties as will bestfacilitate the service of the gun. Lossof cadremen, various details, and casual-ties will necessitate section operationwith a reduced number of personnel tothe extent that it is almost normal forcannoneers to double up on duties.Around-the-clock firing will require .thechief of section to divide the section intoshifts to provide for relief. Two possiblesets of duty combinations are-
(a) Section of 5 men.
1. Chief of section and gunner.2. No. 1 (no other duty).3. Nos. 2 and 3.4. Nos. 4 and 5.5. Driver.
(b) Section of 4 men.
1. Chief of section and gunner.2. No. 1 (no other duty).
28 AGO 4316C
3. Nos. 2, 3, and 4.
4. No. 5 and driver.
(13) To verify the adjustment of sighting andfire control equipment. See paragraphs53 through 65 and TM 9-325 for detailedinstructions on testing and adjustingsighting and fire control equipment.
(14) To check, before they are replaced intheir containers, all rounds not firedwhich have been prepared for firing. Thechief of section personally checks, beforethey are replaced in their containers,all rounds not fired that have been pre-pared for firing, to see that all sevenpowder increments are present in propercondition, that they are assembled inproper numerical order, and that theyare of the same lot number. He alsochecks to see that the lot number on theammunition corresponds to the lot num-ber on the container.
(15) To control movement of the motor car-riage. When it is necessary to move themotor carriage, the chief of section in-structs the drive to start the engines.He then controls the displacement of themotor carriage by voice, interphone, orhand signals.
(16) To supervise use of ammunition. Thechief of section supervises control anduse of proper lot numbers of ammuni-tion as directed by the battery executive.
AGO 4316C 29
22. Gunner
a. List of Duties.
(1) To center the level bubbles on the pano-ramic telescope mount.
(2) To lay the gun for direction.(3) To aline the aiming posts.(4) To set a common deflection on a common
aiming point or on aiming posts afterthe gun has been laid.
(5) To set or change the deflection.(6) To apply special corrections for deflec-
tion.(7) To refer the gun.(8) To make corrections for aiming post dis-
placement.(9') To call "Ready."
b. Detailed Description of Duties.
(1) To center the level bubbles on. the pano-ramic telescope mount. The gunner cen-ters the level bubbles on the telescopemount as part of all operations thatinvolve the use of the panoramic tele-scope. These bubbles are centered priorto using the telescope and the level ofthe mount is verified before firing ((9)below). For direct fire using the two-man, two-sight system (pars. 34-35)the gunner centers the cross-level bubbleonly.
(2) To lay the gun for direction.
30 AGO 4316C
(a) The gun being in position but not laidfor direction, the gunner zeros thesight by the following operations:
1. Alines the azimuth micrometer index(gunner's aid) with the right(fixed) index (fig. 10).
2. Loosens the slipping azimuth microm-eter scale locking nut by turning
.------ ELEVATION KNOB
rELEVATION INDEXES (FINE)
ROTATING HEAD-\
ELEVATION _ade-_OPEN SIGHTINDEXES---SLIPPING AZIMUTH SCALE(COARSE)' : .; --- -LOCKING SCREW
DOOR,,----: ..-V-..AZIMUTH SCALE (NONSLIPPING)
LEVETHROO OUT- -------- AZIMUTH SCALE INDEX
LEVER %KI;~,./ .G " '-AZIMUTH MICROMETER KNOB
LOOKING A
LEFT INDEX-
SLIPPING A -- - SHUTTER
MICROMETER--' \ ., J ---J_--EYESHIELD
SCALE iAZIMUTH MICROMETER
JNDEX (MOVABLE) _
Figure 10. Panoramic telescope M12A7-series.
AGO 4316C 31
Figure 11. Loosening azimuth micrometer scalelocking nut.
it counterclockwise (fig. 11) firmlyholding the azimuth m'crometerknob with h s right hand.
3. Slips the slipping azimuth m'crometerscale until its zero is alined w:th theleft index (fig. 12) and tightens thelocking nut.
4. Turns the azimuth m crometer knobso that the left index and zero ofthe slipping micrometer are alinedwith the zero of the gunner's aidand right index (fig. 10).
32 AGO 4316C
Figure 12. Alining the zero of the slipping micrometerwith the left index.
5. Opens the door and with the azimuthmicrometer knob or rotating headsets the nonslipping azimuth scaleat zero (fig. 13) and closes the door.
6. Loosens the slipping azimuth scalelocking screw; moves the slippingazimuth scale until its zero coin-cides with the index on the outsideof the door (fig. 14).
7. Tightens the locking screw and veri-fies the zero readings. (With thesight thus zeroed the gunner, inindirect fire, will habitually set and
AGO 4816C 33
Figure 13. Turning the nonslipping azimuth scale to zero.
read deflections on the slipping azi-muth scale at the index on the door,setting and reading the last twodigits of the deflection on the azi-muth micrometer.)
(b) The executive commands AIMINGPOINT THIS INSTRUMENT, NO.(SO-AND-SO) DEFLECTION (SOMUCH). The gunner sets the deflec-tion for his gun on the panoramictelescope by disengaging the 'throwout lever and turning the rotating headto the announced hundred mil gradu-
34 AGO 4316C
Figure 14. Slipping zero of the &lipping azimuth scaleto index on door.
ation. He releases the throw out leverand turns off the last two digits ofthe deflection on the azimuth microm-eter scale, using the azimuth microm-eter knob. He then traverses the gununtil his line of sight through thetelescope is on the executive's aimingcircle. He checks to insure that hisbubbles are level and announces, "No.(so-and-so) ready for recheck." As
additional deflections are announcedby the executive he sets them on thesight and traverses the gun so that
AGO 4316C 35
the vertical hair of the reticle is on theaiming circle. When the executive an-nounces, "No. (so-and-so) is laid,"the tube is orientated and should notbe traversed except on order of theexecutive.
(3) To aline the aiming posts. The gun hav-ing been laid as in (2) above the execu-tive may command, AIMING POINT,AIMING POSTS, DEFLECTION 2600,REFER. At this command the gunnersets the panoramic telescope at deflection2600 and, with hand signals, directs No.5 in the alinement of the posts with thevertical hair of the sight reticle (fig. 15).If, because of the nature of the terrain,the posts cannot be set out at deflection2600, the gunner turns the azimuth mi-crometer knob until the slipping azimuthscale is on another even hundred milgraduation. He alines the posts at thisnew deflection. The chief of section re-ports the altered deflection to the exe-cutive: "No. (so-and-so) aiming postsat (so many hundred), 2600 in lake (orother reason)." The executive will thencommand NO. (SO-AND-SO), DE-FLECTION 2600, REFER. At this com-mand the gunner loosens the slippingazimuth scale locking screw and movesthe slipping azimuth scale to deflection2600 (fig. 16). He then tightens the
36 AGO 4316C
Figure 15. Alining aiming posts.
locking screw and verifies the adjust-ment.
(4) To set a common deflection on a commonaiming point after the gun has been laid.The battery having been laid, the exe-cutive may command, AIMING POINT,CHURCH STEEPLE, REFER. At thiscommand, without moving the tubes, thegunners of all guns turn their sights tothe aiming point designated and reportthe deflections to the executive. Theexecutive then commands, COMMONDEFLECTION 2600. At this commandeach gunner loosens the locking screw
AGO 4116C 37
L \CL V ) L
Figure 16. Common deflection 2600.
of the slipping azimuth scale and movesthe scale until 2600 is in coincidencewith the index on the door. The gunnersthen unlock the slipping azimuth mi-crometer scale locking nut, move the
38 AGO 4316C
slipping azimuth micrometer scale tozero, tighten the locking nut, and verifythat the zero is in coincidence with theindex and that the line of sight is stillon the aiming point.
(5) To set or change the deflection. The com-mand is DEFLECTION (SO MUCH).If, for example, the command is DE-FLECTION 2483, the gunner disengagesthe throw out lever with his left thumband turns the rotating head of the sightto 24 (2400). He releases the throw outlever and with right hand turns off theremaining 83 mils on the micrometerscale. He then traverses the gun untilthe vertical hair of the telescope reticleis on the aiming post, being careful thatthe last motion is such as to cause thevertical hair to approach the aimingpoint from the left.
(6) To apply special corrections for deflec-tion. The gunner applies special correc-tions to the announced deflection for hisgun by moving the movable azimuthmicrometer index the proper amount anddirection. For example, the executivecommands SPECIAL CORRECTIONS,DEFLECTION 2665, NO. 1 LEFT 10.The gunner on No. 1 gun first sets offthe announced deflection, then moves theazimuth micrometer index (gunner'said) upward 10 mils. He then resets
AGO 4816C 39
the announced deflection at the indexin its new position. Subsequent deflec-tions, which are set on the azimuthmicrometer scale, will be increased 10mils automatically. The special correc-tion is left on the gunner's aid untilcompletion of the mission or until a newspecial correction is announced. The newspecial correction is set off as com-manded and is not applied algebraicallyby the gunner.
(7) To refer the gun. The command fromthe executive is AIMING POINT THISINSTRUMENT (OR OTHER POINT),REFER. Without disturbing the layingof the gun the gunner turns only thesight until, with bubbles level, the, ver-tical hair of the reticle is on the pointdesignated. He then reports the deflec-tion to the executive: "No. (so-and-so)deflection (so much)."
(8) To make correction for aiming post dis-placement. For details of correcting foraiming post displacement see paragraph43!
(9) To call "Ready." The gun having beenlaid for direction and No. 1 having called"Set," the gunner verifies the laying,moves his head clear of the telescope,and calls "Ready" to indicate that thegun is ready to be fired.
40 AGO 4316C
23. No. 1
The No. 1 cannoneer is the assistant gunner(par. 5b).
a. List of Duties.
(1) To set the site.(2) To apply special corrections for site.(3) To set the elevation.(4) To lay for elevation.(5) To open and close the breech.(6) To call "Set."(7) To fire the gun.(8) To use the rammer.(9) To man the machine gun.
b. Detailed Description of Duties.
(1) To set the site.(a) When site is to be used, the initial
series of fire commands for openingfire will contain the command for site.The command is, for example, SITE305. For subsequent rounds, the sitesetting is changed by a new commandSITE (SO MUCH) (fig. 17).
(b) To set the site, No. 1 turns the angleof site micrometer knob until the an-nounced site is shown. The site isindicated by a scale graduated in hun-dreds of mils from 0 to 6 and a mi-crometer scale graduated from 0 to100 mils. A site of 300 is horizontal.No. 1 first sets the index in the proper
AGO 41160 41
Figure 17. Site 505.
section of the scale in hundreds ofmils and then sets the units on themicrometer scale. The last motion insetting the site should be in the direc-tion of increasing site.
(2) To apply special corrections for site.During any mission when special cor-rections for site are announced, No. 1adds algebraically the site correctionannounced for his gun to each site com-manded. For example, the executivecommands SPECIAL CORRECTIONS,SITE 310, NO. 1 DOWN 2, NO. 2 DOWN3, etc.; 308 is set on the site scale of
42 AGO 4816(C
No. 1 gun; 307 is set on the site scaleof No. 2 gun, etc. Special site correctionsshould be marked in chalk on a conven-ient place inside the compartment.
(3) To set the elevation. To set an elevation,No. 1 sets the site and then sets theannounced elevation on the elevationscale. No. 1 grasps the elevating knoband turns it until the announced eleva-tion is shown, making sure that the lastmovement is in the direction of increas-ing elevation.
(4) To lay for elevation. No. 1 turns thecross-leveling worm knob and centersthe cross-level bubble. Having performedthe duties described in (1), (2), and(3) above, he turns the elevating hand-wheel and elevates or depresses the tubeuntil the longitudinal-level bubble is cen-tered making sure that his eye is directlyopposite the bubble and that the lastmovement is in the direction in whichit is most difficult to turn the handwheel.
(5) To open and close the breech.(a) To open the breech. No. 1 grasps the
breech operating lever handle with hisleft hand, depresses the handle to re-lease the catch, and draws it towardhim and to the rear, opening thebreech.
(b) To close the breech. No. 1.grasps thebreech operating handle with his left
AGO 4316C 43
hand and pushes it forward and awayfrom him until the breech is closedand the latch is engaged. When thebreech is fully closed the latch is auto-matically engaged.
(6) To call "Set." No. 1 calls "Set" whenthe gun has been loaded, the breechclosed, and the gun laid for elevation.
(7) To fire the gun. At the chief of section'ssignal or command NO. (SO-AND-SO)FIRE (par. 21b(7)), No. 1 grasps thelanyard with his right hand and pulls.After firing he releases the lanyard andopens the breech. For action in case ofmisfire, see paragraph 85.
(8) To use the rammer. Normally the ram-mer components will be handled by No.1. The rammer staff is used to extractcartridge cases that cannot be ejectedby the extractor. To extract a cartridgecase, No. 1 inserts the rammer staff inthe bore, and lightly taps the bottomof the inside of the case until it is loos-ened and can be pushed out of the cham-ber. No. 2, standing at the breech, re-ceives the cartridge case in both hands.To extract an unfired round, the pro-cedure described in paragraph 47 willbe followed.
(9) To man the machine gun. The machinegun will be manned by No. 1 when the
44 AGO 4316C
motor carriage is traveling and whendirected by the chief of section.
24. No. 2
a. List of Duties.
(1) To load the gun.(2) In volley fire, to call out the number of
the round and the announced elevation.
(3) When the breech is opened, to inspect thechamber and bore to insure that theyare clear.
(4) To dispose of used cartridge cases.
b. Detailed Description of Duties.
(1) To load the gun. No. 2 grasps the roundwith his right hand at the base of thecartridge case and his left hand in frontof the rotating band. He then faces thebreech and, after an elevation or quad-rant has been announced, inserts theround in the breech and pushes it homewith his right fist (fig. 18). It is ex-tremely important that he use his fist,to guard against getting his fingerscrushed by the closing breechblock. No.2 will be particularly careful to avoidstriking the fuze against any portionof the gun. A round to be loaded willbe held well out of the path of the recoiluntil the tube is again in battery.
(2) To call out the number of the round andthe announced elevation in volley fire.To insure firing the correct number of
AGO 4316C 45
Figure 18. No. 2 loading the gun.
rounds in volley fire, No. 2 calls out thenumber of the round and the elevationas he finishes loading the projectile. Ashe finishes loading the last round, headds, "Last round." For example, whentwo rounds are to be fired at elevation480, he calls out, "Second and last round,480." He should not speak louder thanis necessary to insure his being heard bythe members of his own section.
(3) To inspect the chamber and bore whenthe breech is open to insure that they areclear. No. 2 will inspect the chamberand bore after each round is fired tomake certain that the chamber is clear
46 AGO 4316C
and that the bore is free of residue fromthe charge. He calls out "Bore clear" ifit is clear.
(4) To dispose of used cartridge cases. No.2 will throw used cartridge cases overthe right side of the motor carriage.
25. No. 3
a. List of Duties.(1) To assemble rounds assisted by No. 4.(2) To fuze or change fuzes of projectiles.(3) To set the fuze setter.(4) To set fuzes.(5) To apply special corrections for his gun
to fuze settings.(6) To replace ammunition in containers
assisted by No. 5.
b. Detailed Description of Duties.(1) To assemble rounds. No. 3 receives the
projectile from No. 5 (par. 27b (2)) andassisted by No. 4 (par. 26b (2)) seatsthe projectile in the cartridge case. No.3 inspects each round to see that it isfree from dirt and that the rotating bandis not burred. He wipes off any foreignmatter with a cloth and sets aside anyprojectiles with burred rotating bandsuntil time permits removing burrs witha file.
(2) To fuze or change fuzes of projectiles.No. 3 removes the fuze or closing plug
AGO 4316C 47
from the projectile; removes (or re-places) the supplemental charge, if nec-essary; and screws in the designatedfuze. In assembling fuzes to, or disas-sembling fuzes from shell, only theauthorized fuze wrench should be used.VT fuzes should be screwed in by handand tightened with fuze wrench M18,using only manual force. Do not hammeron the wrench or use an extensionhandle. If a time fuze is used, No. 3removes the safety pull wire from thefuze and, if a booster is inserted, fromthe booster. Boosters without safetypins will not be used.
(3) To set the fuze setter.
(a) Fuze setter M22. The corrector scale isnot used. No. 3 makes certain that thecorrector scale is locked at correctorsetting 30. He releases the time scaleclamping screw marked T and, holdingthe fuze setter by the outer ring, turnsthe body until the index on the bodyis opposite the announced time on thetime scale. He then locks the timescale clamping screw, being carefulnot to disturb the setting. For ac-curacy, No. 3 looks squarely at thescales and indexes in the same mannereach time.
(b) Fuze setter M28 (fig. 19). This fuzesetter has no corrector scale. It has
48 AGO 4316C
two time scale rings; one for use on45-second fuzes and one for 100-secondfuzes. In addition the M28 has a nightlighting device incorporated in thehandle. Except for the corrector scale,operation of the M28 is similar to thatof the M22.
D'' ,
pf .N
Figure 19. Fuze Setter M28.
AGO 48160 49
(4) To set fuzes.(a) Selective superquick and delay fuzes.
When FUZE QUICK is commanded,No. 3 will verify the superquick set-ting. (The slot on the setting sleeveshould be alined with the letters SQ.)When FUZE DELAY is commanded,he will turn the setting sleeve until theslot is alined with the word DELAY.
(b) Combination time and superquickfuzes. These fuzes may be set for timeaction. However, the percussion ele-ment will detonate the round upon im-pact if the time element fails. Afterfuzing the projectile, No. 3 removes.the safety pull wire from the fuze.For percussion action the command isFUZE QUICK M500 (or other desig-nation). No. 3 then verifies that theS on the setting ring is alined with theindex on the fixed ring. If not, he setsit at S.
(c) VT fuzes. Current standard models ofthese fuzes require no setting by anypersonnel.
(d) Setting time fuzes.1. Using fuze setter M22 or M28. After
making the announced settings onthe fuze setter, No. 3 carefullyplaces it over the fuze and turns thesetter until the notch on the timering of the fuze engages the stop on
50 AGO 4316C
the setting ring of the fuze setter.He then pushes down on the fuzesetter until the notch fully engagesthe stop, and turns it until the pawlin the adjusting ring assemblydrops into the notch of the fixedfuze ring. This prevents furtherturning and indicates that the fuzeis set. He then lifts the fuze setterfrom the fuze and makes a visualcheck of the fuze setting to insurethat the fuze ring notch was actuallyengaged and that the fuze is setproperly. If the desired time settingis passed, he replaces the fuze setteron the fuze. and continues rotationin the original direction until thestop pawl of the fuze setter engagesthe fixed notch of the fuze and pre-vents further rotation. The settingis then rechecked visually.
2. Using fuze setter M14 or M27. Theseare wrench-type fuze setters inwhich the fuze time scale is used insetting the fuze. No. 3 engages thekey of these wrench-type fuze set-ters in the notch on the setting ringof the fuze and rotates the settingring or upper cap so as to increasethe time setting until the announcedsetting of the fuze time scale isopposite the index mark on the fuze.
AGO 4316C 51
(5) To apply special corrections to fuzesettings. When special corrections areannounced for his gun, No. 3 will applythe fuze setting special correction; thecommand is for example, TIME 18.2,NO. 1 PLUS 0.7. The No. 3 cannoneeron No. 1 gun must add 0.7 of a secondto 18.2. He continues to apply the cor-rection to all subsequent commands re-ceived for fuze time in that mission oruntil a new special correction is receivedfor his gun.
(6) To replace unused ammunition in con-tainers. Under the personal supervisionof the chief of section and assisted byNo. 5, No. 3 replaces unused ammunitionin containers. He is careful that the lotnumber on the ammunition correspondsto the lot number on the container.
26. No. 4
a. List of Duties.(1) To prepare charges.(2) To assist No. 3 in assembling rounds.(3) To assist No. 3 in setting time fuzes.(4) To place prepared rounds on the rear
deck.(5) To replace increments in the cartridge
case before the rounds are replaced intheir containers.
b. Detailed Description of Duties.(1) To prepare charges. The fire command
52 AGO 4316C
will designate the charge. Upon receiv-ing the cartridge case from No. 5 (par.27b (2)), No. 4 verifies that there areseven powder increments and removesthose numbered higher than the chargedesignated. He then replaces the re-maining increments in the cartridge casein their original numerical order.
(2) To assist No. 3 in assembling rounds.After No. 4 has prepared the charge, heassists No. 3 to assemble the projectileto the cartridge case, taking care thatthe lip of the cartridge case is not dam-aged when No. 3 seats the projectile.
(3) To assist No. 3 in setting time fuzes. Seeparagraph 25b (4) (d) for details of set-ting time fuzes.
(4) To place prepared rounds on the reardeck. As soon as the round is preparedfor firing, No. 4 places it base forwardon the rear deck of the motor carriageready for No. 2 to pick up and load intothe breech. When No. 2 is ready to loadthe gun and rounds have not been pre-viously prepared, No. 4 passes the pre-pared round directly to No. 2. Thismovement is made in such a manner thatNo. 2 is able to grasp the round with hisleft hand in front of the rotating bandand his right hand on the base of thecartridge case, making sure that the pro-
AGO 4316C 53
jectile and cartridge case do not sepa-rate.
(5) To replace increments in the cartridgecase before rounds are replaced in theircontainers. Under the personal super-vision of the chief of section, No. 4 re-places increments in cartridge cases forall ammunition prepared for firing butnot fired. He carefuly checks to see thatall seven increments are present, in theproper condition, assembled in theproper numerical order, and that the lotnumber is the same as the lot number ofthe container.
27. No. 5
a. List of Duties.(1) To set out aiming posts.(2) To remove ammunition from containers.(3) To assist No. 3 in replacing unused am-
munition in containers.b. Detailed Description of Duties.
(1) To set out aiming posts. When so di-rected by the chief of section, No. 5 setsout the aiming posts under the guidanceof the gunner (par. 22b(3)).
(2) To remove ammunition from containers.No. 5 removes the taped end from thecartridge case portion of the ammunitioncontainer and tilts the container so thatthe cartridge case can be taken by No. 4.He then reverses ends of the container
54 AGO 4316C
and repeats the process so that the pro-jectile is received by No. 3. During ex-tended firing when ammunition is de-livered to the section, No. 5 may be onthe ground in rear of the vehicle. Whenhe is working on the ground, he disas-sembles the ammunition and places theprojectile and cartridge case on the reardeck of the motor carriage where Nos.3 and 4 can reach them easily.
(3) To assist No. 3 in replacing unused am-munition in containers. See paragraph25b (6) for details of replacing preparedrounds of ammunition in containers.
28. Driver
a. List of Duties.(1) To move the cartridge if large shifts are
necessary.(2) To perform maintenance in stabilized
situations.(3) To assist No. 5 in handling ammunition.(4) To repair wire.
b. Detailed Description of Duties.(1) To move the carriage if large shifts are
necessary. Until the direction of fire isdefinitely determined and at such othertimes as necessary, the driver will be athis post prepared to move the motorcarriage. At the direction of the chiefof section, the driver will shift the car-riage to permit a large deflection shift
AGO 4316C 55
to fall within the on-carriage traverselimits.
(2) To perform maintenance in stabilizedsituations. When firing is stabilized andthe engines are not running, the driverperforms such maintenance as may beaccomplished without interfering withthe firing of the gun. Any disassembliesor maintenance operations that will ren-der the vehicle immobile for any periodof time must be ordered by the chiefof section.
(3) To assist No. 5 in handling ammunition.When No. 5 is unable to keep up with theammunition requirements dictated by ahigh rate of fire, the chief of sectionmay direct the driver to assist in thehandling of ammunition.
(4) To repair wire. The driver, whendirected by the chief of section, willmake repairs to the intra-battery com-munication system.
Section II. DIRECT LAYING, GENERAL
29. General
a. Firing by direct laying is a technique thatdemands special training. The section mustoperate as an independent unit. Training in directlaying is based on the technique employed inindirect laying. Targets taken under fire by the
56 AGO 4516C
section in direct laying usually those capable ofreturning fire on the section at point-blank range;therefore, the speed and accuracy required in in-direct laying becomes even more important fordirect laying missions.
b. There are two basic systems of direct lay-ing for use with the 105-mm howitzer: The two-man, two-sight system (pars. 33 to 37 incl.) wherethe gunner, using the panoramic telescope, laysfor direction, and No. 1, using the elbow tele-scope, lays for range; and the one-man, one-sightsystem (pars. 38 to 42) where the gunner laysfor both direction and range using the panoramictelescope.
c. The chief of section will designate the sys-tem of laying to be used when firing by directfire methods. Selection of the system is depend-ent upon the type which can more effectivelyengage the target. Training must include bothsystems of direct laying.
d. For additional information on direct laying,see FM 6-140.
30. Preparation of a Range Card
a. The chief of section is responsible for defensein his assigned sector, but he should be preparedto fire on targets in other sectors.
b. As soon as possible after occupation of posi-tion, the chief of section measures or estimatesthe ranges to critical points in likely avenues of
AGO 4816C 57
ILL REE-HILL 0
O /RCHARD
HILL
Figure 20. Range card for direct laying.
approach for enemy tanks and vehicles. For quickreference he prepares a range card (fig. 20) uponwhich he notes these ranges.
c. If there are no prominent terrain features,stakes may be driven into the ground at criticalpoints for reference. As time permits, the rangecard will be improved by replacing estimatedranges with more accurate ranges obtained byfiring, pacing, taping, vehicle speedometer read-ing, map measurements, or survey.
BRU AGO 4316C58 AGO 4316C
might hinder observation. Care should be takennot to give away the location of the position.
32. Conduct of Fire
a. Types and Selection of Targets for DirectLaying. Targets for direct laying usually consistof hostile vehicles, tanks, and personnel threaten-ing the battery. Enemy personnel, whether aloneor accompanying tanks, will seldom present them-selves as a clearly defined target. Normally, at-tacking infantry, using all available cover, revealthemselves only fleetingly. Accordingly , fire isconducted on the area containing the attackersrather than upon the individuals. Tanks usuallyattack in groups and may be accompanied by in-fantry. Normally, first priority is given to attackof those targets within the assigned sector of theweapon and second to targets in other sectors.Priority within the assigned zone is given to-
(1) Tanks at short ranges, threatening tooverrun the position.
(2) Hull down stationary tanks covering theadvance of other tanks.
b. Ammunition and Fuzes.
(1) General. For close-in fires a variety offuzes and shells are available. Whenusing high explosive shell, charge 7 isused habitually for speed, ease in adjust-ment, imparting forward motion to frag-ments, and more effective fuze action.
AGO 4816C 59
The flat trajectory resulting from use ofcharge 7 coupled with dug-in guns maymake extremely close-in fire impossibledue to projectiles skipping without de-tonating on impact. At ranges of 200 to400 yards fuzes may fail to functionon hard, flat ground; however, prepara-tion of sectors of fire will remedy thissituation. The terrain may be preparedfor direct fire by placing mounds of sand-bags, dirt, or logs in the gun's sector ofresponsibility. When direct fire is placedon these or other previously selectedpoints as they are approached by anattacking force, the necessity for adjust-ing fire is reduced.
(2) Ammunition. Ammunition may be HE,HEAT, or white phosphorus (WP).HEAT is designed for, and is highlyeffective in, antitank and antivehiclefires. Shell HE is ideally suited for anti-personnel fire and is effective againstvehicles and tanks. WP may be usedto set immobile tanks and vehicles onfire, to further restrict defiles, and toproduce casualties. However, considera-tion must be given to the effect on thedefense of the resulting smoke screen.
(3) Fuzes. HEAT projectiles contain basedetonating fuzes. WP ammunition isfuzed with a superquick-delay fuze while
60 AGO 4316C
in direct fire HE may be used with fuzesquick, delay, or time.
(a) Fuze quick is the most desirable fuzeto use with HE shell on close-in fires.It is highly effective and, since no fuzesetting is required, is much faster touse.
(b) The time required to set the fuze andto adjust the point of impact for maxi-mum ricochet effect makes fuze delayless desirable than fuze quick. Whenusing fuze delay to gain ricochet effect,the point of impact is adjusted 10-30yards in front of the target. If lessthan 50 percent of the bursts arericochet, the fuze should be changedto quick.
(c) Fuze time is the least desirable fuzefor close-in fires. At short fuze set-tings, variations in time of burninggive wide range dispersion. Hence,this fuze should be used only forranges of more than 1000 yards. Theareas covered effectively by air andricochet bursts are similar.
c. Trajectories. Trajectory characteristicschange with the type of ammunition and thecharge fired. The following trajectory character-istics govern the conduct of fire:
(1) Ranges from 0 to 400 yards using HEATor ranges from 0 to 600 yards using HE
AGO 4316C 61
charge 7. Within these range limits, thetrajectory will be flat enough to preventan 8-foot tank from passing safely underit. Fields of fire and terrain allowing,the upper range limits for the ammuni-tion and charge used are the ideal atwhich to open fire. Fire can then beconducted over the maximum time with-out misses if deflection is correct. Alsothere is less risk of obscuring the targetwith the smoke from a short burst.
(2) Ranges from 400 to 700 yards usingHEAT, or 600 to 1000 yards using HEcharge 7. These range limits include thezone in which the trajectory is suffi-ciently flat to permit direct estimationof range without actually bracketing thetarget. Assuming little dispersion, if ahit is obtained at the bottom of an 8-foot tank firing at the upper range limit,700 yards for example, with HEAT, theadding of a 100-yard range change willresult in a round that will just brushthe top of the tank. During adjustmentwithin this zone, range changes shouldseldom be more than 100 yards, and fre-quently range changes of 50 yards willbe sufficient. The upper limits mentionedherein are the greatest ranges at whichfire should be opened unless tactical con-ditions require otherwise. A trained
62 AGO 4816C
crew should obtain hits by the secondshot.
(3) Ranges from 700 to 1300 yards usingHEAT or 1000 to 1800 yards using HEcharge 7. This zone includes the rangesat which hits are only reasonably pos-sible. Bracket methods are normally usedto obtain adjustment in this zone. Thereis more dispersion in this zone, and fireshould not be opened at these rangesunless surprise is not important.
(4) Ranges over 1300 yards using HEAT, orover 1800 yards using HE charge 7. Atranges over 1300 yards using HEAT orover 1800 yards using HE charge 7,direct laying is not advisable againstmoving targets. Dispersion is the con-trolling factor.. Ranges must be knownaccurately or determined by bracketing.At these ranges the slope of fall of theprojectile becomes so great that a hit ona moving target is very difficult to obtain.
d. Vertical Displacement Table. Vertical dis-placement is the change in the point of burst (upor down) between two rounds fired at an uprighttarget at different range settings. Table III showsthe vertical displacement for a 100-yard rangechange at various ranges, firing shell HEAT andshell HE charge 7. The use of vertical displace-ment in direct firing is explained in FM 6-140.
AGO 4316C 63
Table III. Vertical Displacement (Feet)per 100-Yard Range Change.
Range a a Range(yards) W: W Remarks Ia (yards)
.I
100 1 Start firing using 400 0.5 100200 2 yard range setting. 1.5 200300 3 2 300
2.5 4003.5 500
400 4 Start firing with esti- 4 600500 5.5 mated range. Increase 5 700600 6 or decrease by multi- 5.5 800700 8 ple of 50 or 100 yards. 6 900
Bracketing not neces- 7 1000sary.
800 9 Bracket target (get 8 1100900 10.5 bursts over and short) 9 1200
1000 11.5 to obtain hit. 10 13001100 13 . 10.5 14001200 14.5 11.5 15001300 16 13 1600
14 170014.5 1800
Over 1300 ---- At ranges over 1300 ____ Over 1800yards using HEATor over 1800 yardsusing HE charge 7,direct firing is too in-accurate to be usedagainst moving tar-gets (c(4) above).
Note. Computed from data obtained from FT 105-H-4.Two-man, two-sight system.
64 AGO 4316C
Section III. DIRECT LAYING, TWO-MAN, TWO-SIGHTSYSTEM
33. Chief of Section
a. List of Duties.(1) To conduct the fire of his gun.(2) To alert his section.(3) To identify or select the target.(4) To select the charge, fuze, and pro-
jectile.(5) To give direction of the target.(6) To determine the lead in mils.(7) To give the command for range.(8) To give subsequent commands based on
observed effect.
b. Detailed Description of Duties.(1) To conduct the fire of his gun. The chief
of section conducts the fire of his gunwhen the executive commands TARGET(IDENTIFICATION), FIRE AT WILL,or simply FIRE AT WILL.
(2) To alert his section. The command toalert the section is 1. CANNONEERS,2. POSTS. At the command, membersof the section move to their posts to beready for the initial fire command. Ifthe target is outside the maximum tra-verse of the gun, the alert is followed bythe necessary signals to the driver to getthe motor carriage pointed in the ap-proximate direction of the target.
AGO 4316C 65
(3) To identify or select the target. If theexecutive designates an object as thetarget, the chief of section must identifythis target correctly. If the target is agroup of tanks or other objects, thechief of section selects the target which,in his estimation, is the greatest threatto his own position or the position of thesupported troops. He repeats the identi-fication to his section, employing theminimum number of words, such asTANK, MOVING TANK, ENEMY IN-FANTRY, (OR OTHER TARGET).
(4) To select the charge, fuze, and projectile.The chief of section commands the ap-propriate items in sequence such asSHELL HE, CHARGE 7, FUZE, orSHELL HEAT. He selects the charge,fuze, and projectile in accordance withthe consideration contained in paragraph32.
(5) To give the direction of the target. Thechief of section ascertains the directionof movement of the target and com-mands TRAVERSE RIGHT (LEFT),STEADY-ON. While giving these com-mands he looks along the tube orthrough the open sight of the panoramictelescope.
(6) To determine the lead in mils. Theamount of lead in mils is determined bythe speed of the target, the range, the
66 AGO 431GC
course, and the ammunition being fired.Figure 21 shows approximate' initialleads that should be used for variousspeeds when firing HEAT and HEcharge 7. The initial command for leadis LEAD (SO MUCH). During adjust-ment the lead is changed by the commandRIGHT (LEFT) (SO MUCH).
LEAD
SPEEDTAHGET TRAVELLING PERPEN- TARGET TRAVELLINGDICULAR TO LINE OF FIRE. 45
°TO LINE OF FIRE.
HE-AT CHARGE 7 HE-AT CHARGE 7
SLOW (O-10 MPH) 5 5 5 5
MEDIUM (10-20 MPH) 20 15 10
FAST (OVER 20 MPH) 30 25 20 20
Figure 21. Approximate leads.
(7) To give the command for range. Thecommand is RANGE (SO MUCH). Therange commanded by the chief of sectionis that range to be set on the sightreticle. During adjustment of fire, rangeis corrected by the command ADD(DROP) (SO MUCH).
(8) To give subsequent commands based onobserved effect. The chief of section ob-serves each round and gives the neces-sary commands for changes in lead andrange to adjust the burst to the target.
AGO 4316C 67
34. Gunner
a. List of Duties.(1) To center the cross-level bubble on the
panoramic telescope mount.(2) To set the elevation indexes and the
azimuth scales of the panoramic tele-scope at zero.
(3) To lay on the target with the announcedlead.
(4) To track the target.(5) To command FIRE.(6) To follow subsequent commands.
b. Detailed Description of Certain .Duties.(1) To lay on the target with the announced
lead and track the target.(a) Prior to any direct fire mission the
gunner verifies that the movableazimuth micrometer (gunner's aid)index is set at zero.
(b) If the slipping azimuth and slippingmicrometer scales have not beenslipped, the gunner zeros these twoscales.
(c) If only the slipping azimuth scale hasbeen slipped, the gunner disregardsscale. He opens the door over the non-slipping azimuth scale and sets thatscale at zero. The micrometer scale isbrought to zero.
(d) If both the slipping micrometer scaleand the slipping azimuth scale have
68 AGO 4316C
been slipped, the gunner opens theazimuth scale door and turns the non-slipping azimuth scale to zero. Hethen turns the azimuth micrometerknob until the left index of themicrometer matches the right index.
(e) The operations described in (a), (b),(c), and (d) above make theline ofsight of the telescope parallel to theaxis of the bore. The gunner thentracks target using the traversinghandwheel to keep the appropriatevertical grid line in the reticle of thetelescope on the center of the visiblemass of the target. The announced lead
40 30 20 10 10 2030 40
Fige 22. Gunner's sight picture, two-man, two-sight
Figure 22. Gunner's sight picture, two-man, two-sightsystem (lead 15 mils).
AGO 4316C 69
is measured on the horizontal reticlescale (fig. 22). In the two-man, two-sight system the vertical location(range) of the target is controlled byNo. 1. If time does not permit thechief of section to announce the lead,it is estimated by the gunner.
(2) To command FIRE. After No. 1 hascalled "Set" and when ready, the gun-ner commands FIRE.
35. No. 1
a. List of Duties.(1) To lay for range, using the elbow tele-
scope.(2) To track the target.(3) To call "Set" when the gun is loaded
and the correct range line is on thecenter of the visible mass of the target.
(4) To follow subsequent commands.b. Detailed Description of Certain Duties. In
direct laying, using the elbow telescope, No. 1 setsoff the range commanded by the chief of sectionby placing the appropriate range line in the reticleof the elbow telescope on the center of the visiblemass of the target; he tracks the target with theelevating handwheel maintaining the proper rangeline on the center of the target (fig. 23).
36. No. 5
a. List of Duties.(1) To open and close the breech.
70 AGO 4316C
_ -+1o0- -
4 1 =
i1 161 20
- ,28-
Figure 23. No. 1's sight picture, elbow telescope MISAIC,two-man, two-sight system, shell HEAT, range 800yards.
(2) To indicate that the gun is loaded bytapping No. 1 on the shoulder.
(3) To fire the gun at the gunner's command.b. Detailed Description of Certain Duties. No.
5 will take position in rear of No. 1 and willopen and close the breech and fire the gun. Hetaps No. 1 with his right hand; when the gun isloaded, he pulls the lanyard with his left handwhen the gunner commands FIRE.
37. Remainder of Section
The remaining cannoneers perform their dutiesas prescribed for indirect laying.
AGO 4816C 71
Section IV. DIRECT LAYING, ONE-MAN, ONE-SIGHTSYSTEM
38. Chief of Section
The duties of the chief of section are the sameas in the two-man, two-sight system (par. 33).Since the panoramic telescope's reticle range linesare graduated for shell HE, charge 5, the chiefof section must consider the ammunition beingfired and announce the appropriate range setting.At short ranges (under 2400 yards) the eleva-tions for charge 7 are almost exactly half thoseof charge 5. The reticle can be used for charge7 by laying with half the true range. When firingshell HEAT the correct range setting is deter-mined and announced by the chief of section.
39. Gunner
a. List of Duties.(1) To match the elevation indexes of the
panoramic telescope mount and set theazimuth scales of the sight at zero.
(2) To center the cross-level bubbles on thepanoramic telescope mount.
(3) To lay on the target with the announcedlead and range.
(4) To track the target.(5) To command FIRE.(6) To follow subsequent commands.
b. Detailed Description of Certain Duties. Thegunner matches the sight mount elevation indexeson the actuating arm and rocker and those on the
72 AGO 4316C
elevation knob and shaft. He then sets the eleva-tion indexes and azimuth scales of the panoramictelescope at zero. Action in regard to slippingscales is as described in paragraph 34. Afterlaying approximately on the target, he centersthe telescope mount cross-level bubble. He thenlays on the target with the announced lead andrange measured on the scales of the reticle (fig.24). Other duties are performed as in the two-man, two-'sight system (par. 34).
CHARGE 5 05-H 4,5
Figure 24. Gunner's sight picture, one-man, one-sightsystem (lead 15 mils, range 600 yards).
40. No. 1
The duties of No. 1 when using the one-man,one-sight system are to open and close the breech,
AGO 4316C 73
to call "Set" when the gun is loaded, and to firethe gun at the gunner's command FIRE.
41. Remainder of the Section
The remaining cannoneers perform their dutiesas prescribed for indirect laying.
74 AGO 4816C
CHAPTER 6
TECHNIQUES AND SITUATIONS THAT REQUIRESPECIAL ATTENTION
42. Precision in Laying
a. Sighting and laying instruments, fuze set-ters, and elevating and traversing mechanismsmust be properly operated to reduce the effectsof lost motion. For uniformity and accuracy thelast motion in setting instruments and in layingshould be in the direction prescribed in thismanual. To insure accurate laying, personnel wholay the gun must be required to verify the layingafter the breech has been closed.
b. The line of sight when setting and readinga scale or centering a bubble should be at a rightangle to the scale or level vial to prevent parallaxerrors. Bubbles should be centered exactly.
c. For uniformity and accuracy in laying onaiming posts, the vertical hair in the reticle ofthe panoramic telescope should be alined with theleft edges of the aiming posts.
43. Aiming Points and Displacement Corrections
a. General. After the gun has been laid initiallyfor direction it is referred to the aiming postsand usually to one or more distant aiming points.An aiming point must have a sharply defined
AGO 4316C 75
point or vertical line clearly visible from the gunso that the vertical hair of the panoramic tele-scope can be alined on exactly the same placeeach time the gun is relaid.
b. Distant Aiming Point. A distant aimingpoint is one at sufficient distance (at least 2000yards) so that normal displacements of the gunin firing or traverse will not cause a horizontalangular change in direction (with the same set-tings on the azimuth scales) of more than l/2 mil.The executive officer usually designates the distantaiming point or points to be used.
c. Aiming Posts.
(1) Two aiming posts are used for each gun.Each post is equipped with a light foruse at night. The most desirable distancefrom the gun to the far aiming post is100 yards, considering accuracy of lay-ing, visibility, and ability to control theaiming post lights. First the far post isset up and alined. The near post is thenset up and alined halfway between thefar aiming post and the gun (par. 22b(3)). The vertical hair of the telescopemust be on the left edge of the aimingposts for proper alinement. To insureequal spacing of aiming posts, the dis-tance to both the near and the far postshould be paced by the same man. Whereground conditions make pacing inaccu-rate, the distance from the gun to theposts may be measured using the pano-
76 AGO 4316C
ramic telescope and the aiming post asmeasuring devices ( (4) below).
(2) For night use, the aiming post lightsshould be adjusted so that the far onewill appear several feet above the nearone. On flat terrain this may be accom-plished by using only the lower half ofthe near post. The two lights placed inthis way will establish a vertical line forlaying the gun.
(3) Since the panoramic telescope is mountedat considerable distance from the centerof rotation of the top carriage, largechanges in deflection will cause misaline-ment of the aiming posts. Placing theaiming posts to the left front at a deflec-tion of approximately 2600 when the gunis in the center of traverse will keepthis misalinement to a minimum andstill allow for maximum visibility.
(4) To measure the distance from gun toaiming posts the stadia method may beemployed, using the panoramic telescopeand the aiming post as measuring de-vices. No. 5 cannoneer, when setting outthe aiming posts, holds the upper sectionof one of the aiming posts in a horizontalposition, perpendicular to the line ofsighting. The gunner measures the lengthof this section in mils on the reticle ofthe panoramic telescope. For example,the upper section of the aiming post is41/2 feet long so that it measures 15 mils
AGO 48160 77
when it is 100 yards from the gun. Theproper location for the near post, in thiscase, would be at the point at which the41/2-foot section measures 30 mils. Inmany cases, the ideal spacing of 50 and100 yards cannot be obtained, but theposts will be properly spaced when thenear post is set at a point 'where onesection of the aiming post (41/2-feet)held horizontally measures twice thenumber of mils it measured at the farpost location. This measurement may beperformed at night by attaching thenight-lighting devices on the ends of onesection of an aiming post and holding ithorizontally.
d. Correction for Displacement of AimingPosts. When the gunner notes that the verticalhair of the telescope's reticle is displaced fromthe line formed by the two aiming posts (or aim-.ing post lights), he lays the gun so that the far-aiming post (light) appears exactly midway be-.tween the near aiming post (light) and the ver--tical hair (fig. 25). If the displacement is due,to traversing the gun, the gunner continues to layas described above. If the displacement is due to.progressive shifting of the carriage from shockof firing or other cause, the gunner will notifythe chief of section, who, at the first lull in firing,.will notify the executive and request permissionto realine the aiming posts. To realine, the gun is.laid with the far post midway between the near-post and the vertical hair (fig. 25). The far aim--
78 AGO 4316C:
ing post is moved into alinement with the verticalhair of the telescope and then the near aimingpost is alined. If terrain conditions make it im-practicable to move one of the two aiming posts,the gun is laid for direction and referred to theaiming post that cannot be moved. This deflectionis reported to the executive. The other post isalined using the method described in paragraph22b (3) and the azimuth micrometer scale isslipped to retain the same deflection that was usedprior to realinement of the aiming posts.
FAR FAR POSTFAR POSTNEAR POST NEAR POST
40 :0 Z 019 09 -0 00 o 0 02030 0
LEFT RIGHTDISPLACEMENT DISPLACEMENT
Figure 25. Gunner's sight picture of aiming posts in properrelationship when correcting for displacement.
44. Testing Target
If the regular target, TT 7159214, or a visibledistant aiming point is not available, a testingtarget may be improvised either by drafting theaiming diagrams to the correct measurements orby the following technique:
AGO 4316C 79
a.. Carefully bore sight the gun on a distantaiming point.
b. Place a flat piece of masonite, wallboard, orsimilar material covered with a sheet of weatherresistant paper 50 yards in front of the gun sothat its face is perpendicular to the line of sightthrough the tube. To render the testing targetstable, it may be fastened to a stand similar tothat shown in figure 26.
Figure 26. Rear view of a bore sighting target stand.
80 AGO 4316C
c. Without disturbing the relationship of thetelescopes to the tube, mark on the paper thecenters of the lines of sight through the tele-scopes and the tube.
d. From the centers marked, construct aimingdiagrams such as are found on standard testingtargets.
e. For use in either leveling or canting the testtarget a mil scale may be drawn at the bottomof the target. A small nail at the top marks thecenter from which the arc was drawn and pro-vides a hook from which to suspend the plumb line(fig. 27).
II
, ' 15.005" !
LINEL
(N OI 10 SCSl,) SZ
Figure 27. Vertical reference lines and mil scale drawn ontesting target.
AGO 4316C 81
f. Vertical reference lines may be drawnthrough the centers of each of the diagrams (fig.27). These lines may be used when the trunnionscannot be leveled, by setting the test target withthe cant angle of the gun. The target is rotateduntil the line of sight through the tube tracks thereference line when the tube is elevated or de-pressed. Similarly, the panoramic telescope shouldbe adjusted so that its reticle tracks the appro-priate reference line when the tube is elevatedor depressed.
g. To facilitate bore sighting in darkness, drilla Y16-inch hole through the mounted testing targetat the center of each aiming diagram. A flash-light held against the target behind the appro-priate hole provides an aiming point for use inblackout conditions. Fasten patches of felt pad-ding on the back of the target covering the regionsof each hole so that light from the flashlight willnot escape. The flashlight must be lighted onlyafter it is placed firmly in position. Care must betaken to prevent disturbing the position of thetesting target.
45. Cease Firing
The command CEASE FIRING is normallygiven to the gun section by the chief of section,but in emergencies anyone present may give thecommand. At this command, regardless of itssource, firing will cease immediately. If the gunis loaded, the chief of section will report thatfact to the executive. The executive acknowledgesthis announcement by saying "No. (so-and-so)
82 AGO 4316C
loaded." If CEASE FIRING came from the firedirection center, firing is resumed at the announce-ment of the elevation. If CEASE FIRING camefrom within the firing battery, the executive willinvestigate the condition that caused the com-mand to be given. When corrected, firing is re-sumed at the executive's announcement of theelevation.
46. Changes in Data During Firing
a. Before Gun Is Loaded. Corrected data isannounced. The new data is then set off and firingresumed at the announcement of the elevation.
b. After Gun Is Loaded. The command CEASEFIRING is given. If no change in fuze setting isrequired, or if the gun is loaded with percussion-fuzed shell, the new data is set off and firing isresumed at the announcement of the elevation. Ifthe gun is loaded with time-fuzed shell, and thedata requires a change in fuze setting, the chiefof section will suspend firing and that fact will bereported to the executive; for example, "No. 2loaded, time (so much)." The gun will not be un-loaded unless directed by the executive. In con-tinuous fire, changes in data are so applied as notto stop the fire or break its continuity.
47. To Unload the Gun
a. A complete round, once loaded, should alwaysbe fired in preference to being unloaded, but mili-tary necessity may dictate otherwise.
b. When the command UNLOAD is given, No.1 opens the breech slowly; No. 2 standing at the
AGO 4316C 83
breech, receives the ejected round or cartridgecase.
c. Should the extractor fail to extract the com-plete round, the staff and unloading rammer(head) is used. This will be done only under theimmediate supervision of an officer. He inspectsthe recess in the head of the rammer to assurethat it is free from obstructions. No. 1 then in-serts the rammer in the bore until the head in-closes the fuze and comes into contact with theprojectile. He pushes and, if necessary, taps therammer staff slightly, or operates the spring-operated rammer, until the round is dislodged.He then pushes it out of the breech and No. 2receives it.
d. If the cartridge case is extracted but not theprojectile, No. 1 fills the chamber with waste andcloses the breechblock. He dislodges the projectileas in c above. No. 2 then opens the breech, re-moves the waste, and receives the projectile asNo. 1 pushes it to the rear.
e. For further information on unloading, seeFM 6-140 and TM 9-325.
f. In case of a misfire, the instruction containedin paragraph 85 will be followed.
48. Care of Ammunition
a. To insure uniform results in firing, to pro-long the life of the tube, and to avoid accidents,care must be exercised in the storage and handlingof ammunition at the battery. Provisions of TM9-1900 applicable to field service should be fol-lowed carefully. In the field, conditions existing in
84 AGO 4316C
each position will determine the amount of time,labor, and materials required to store and pre-serve the ammunition adequately. If the positionis to be occupied for only a few hours, a tarpaulinspread on the ground may be sufficient; for longerperiods of time more elaborate facilities shouldbe provided.
b. Ammunition must be protected from damage.When ammunition is received, it should be sortedinto lots and placed in the best available storage.Powder temperature should be kept as uniformas possible. Ammunition data cards should bekept until after all ammunition for that lot isexpended. Ammunition should be left in con-tainers until its early use is expected. Protectionshou!d be provided against moisture, dirt, directrays of sun, and, as far as practicable, hostileartillery 'fire and bombing. Protection fromweather, dirt, and sun may be obtained by the useof tarpaulins below and above ammunition anddunnage between the layers. Projectiles piled inthe open should be raised off the ground by at least6 inches. If drainage is not good, ditches shouldbe dug around piles. A liberal use of dunnageshould be made between layers and coveringtarpaulins should be raised from the stack at least6 inches to insure adequate ventilation. Eachstack should contain not more than 75 rounds andshould be not more than 4 layers high. Stacksshould be at least 10 yards apart.
c. For further information on care of ammuni-tion, see FM 6-140, TM 9-325, TM 9-1900, andTM 9-1901.
-AGO 4316C 85
49. Ammunition Assembly Trough
To speed up the assembly of semifixed ammuni-tion after the power charge has been preparedand to guard against accidental pinching of theassembler's hand, assembly troughs may be im-provised. Specifications for a type trough areshown in figure 28.
F--------- --------H--24" .
TAMMUNITION TROUGH
Figure 28. Ammunition assembly trough.
50. Section Data Board
When positions are occupied for more than afew hours, data boards may be used by eachsection for recording such items as deflections toaiming points, calibration corrections when ap-propriate, minimum elevations, data for barragesand counterpreparations, and other data whichmay be needed quickly. If such informationassumes a standard pattern, the section may painta form on the inside of the hull and chalk in thevarious items of information in the appropriatespaces.
86 AGO 4816C
51. Hand Signals
Standard hand signals are used to indicate tothe driver the proper movement of the motorcarriage. Dismounted signals are given facingthe driver and are as illustrated in FM 21-60and FM 25-10.
52. Touch Signals
The following are touch signals used by thechief of section or the gunner when mounted toindicate to the d-iver the proper movement ofthe motor carriage.
a. Move Forward. Tap slowly between shoulderblades.
b. Increase Speed. Tap rapidly between shoul-der blades.
c. Halt. Steady pressure on top of the head.d. Decreases Speed. Tap lightly on top of the
head.e. Move Backward. Tug on back of collar.f. Change Direction. Pull on right or left
shoulder until turn is completed.g. Sound Siren. Run thumb rapidly upward be-
tween shoulder blades.
AGO 4816C 87
CHAPTER 7
BORE SIGHTING AND BASIC PERIODIC TESTS
Section I. GENERAL
53. Purpose and Scope
The purpose of this chapter is to outline theprocedures for bore sighting and for making basicperiodic tests of on-carriage fire control equip-ment. ,The procedures covered will include onlythose that may be accomplished at battery level.
54. Equipment
The following equipment is needed for perform-ing bore sighting and periodic tests:
a. Bore Sights. Front and rear bore sights orimprovised substitutes are necessary for both boresighting and testing. If bore sights are not avail-able, cross hairs may be fastened on the muzzleand the firing pin hole in the breechblock bushingmay be used as a rear sighting guide by removingthe firing lock from the closed breechblock.
b. Testing Target. A testing target (par. 44)or suitable substitute is needed for both boresighting and testing. If the testing target is notavailable, a clearly defined aiming point 2000yards or more from the gun may be used forbore sighting.
88 AGO 4316C
c. Tools. The section equipment includes all thenecessary tools for bore sighting and testing. Caremust be taken in using the screw drivers andwrenches to insure that damage to fasteningsdoes not result through carelessness or the use ofinappropriate tools.
d. Plumb Line. Although not essential for boresighting, it is necessary that a plumb line beused in the basic periodic test in order to obtainmaximum accuracy. The farther from the gunthat the plumb line is placed, the longer the linemust be. For example, to be effective at 6 feet infront of the tube, the line must be at least 30
Figure 29. Plumb line suspended from tree.
AGO a8160 89
feet long. To keep such a long plumb line taut itmay be necessary to add weight to it. Wrenchesor rocks may be used. The tendency of the weightto swing may be decreased by placing a bucketcontaining water or other liquid under the plumbline so that the plumb bob is partially immersedin the liquid. A plumb line strung from a buildingor tree as in figure 29 is more desirable andshould be used if possible. Units in garrison mayfind it convenient to rig a plumb line on a building.The line may then be nailed in place so that itcan be used permanently.
Section II. BORE SIGHTING
55. General
a. Description. Bore sighting is the process ofverifying that the alinement of the on-carriagefire control equipment is parallel both for deflec-tion and, except for the aiming circle method,for elevation with the axis of the tube of 'theweapon. Any misalinement discovered is correctedas described in paragraph 57. Bore sighting isconducted by section personnel before firing andduring lulls in firing.
b. Methods. Four methods of bore sighting the105-mm howitzer are-
(1) Testing target method.(2) Distant aiming point method.(3) Aiming circle method.(4) Standard angle method.
c. Leveling. Prior to starting the tests the gunshould be placed in its center of traverse. Al-
90 AGO 4816C
though it is not absolutely necessary to level thetrunnions for bore sighting, it is advisable to doso whenever possible. Accurate results can be ob-tained more readily if the trunnions are level,since a corresponding tilt does not have to beintroduced in the panoramic telescope mount andin the testing target. The trunnions should beleveled by moving the carriage to level groundor by blocking up one side of the motor carriage.
(1) Plumb line. The best method to checkleveling is by means of the plumb line.The line is suspended directly in front ofthe axis of the bore. When the trunnionsare level, the line of sight should trackthe plumb line as the tube is depressedand elevated throughout the limits ofelevation. If the trunnions cannot beleveled without shifting the carriage,and the cant is only slight, the followingtechnique may be used. Traverse thetube from center and shift the carriageto bring the line of sight back on theplumb line. -Elevate the tube to deter-mine whether it more nearly tracks theplumb line. Repeat this experiment un-til the line of sight tracks the plumb lineexactly.
(2) Gunner's quadrant. If the plumb linecannot be used, a check of approximateleveling may be accomplished by useof the gunner's quadrant placed on thebreech ring parallel to the trunnions.In leveling operations using the gun-
AGO 4316C 91
ner's quadrant, a quadrant that has beentested (par. 62) and found to be accu-rate is required.
(3) Scribed lines. When it is impossible tolevel the trunnions the cross-level bubblecannot be used. If the tube cannot beleveled the longitudinal-level bubble can-not be used. To permit bore sightingwhen either of these conditions exist,lines should be scribed on the sightmount after a basic periodic test (pars.61-64) when the mount is in correctadjustment. These scribed lines can bematched later, when leveling is impos-sible, to retain the same relationshipbetween the axis of the bore and movingparts of the on-carriage sighting equip-ment. After a basic periodic test withthe tube and sighting equipment in per-fect alinement, use a knife blade or othersharp metal point to scribe lines asshown in figure 30. Care should be takenthat the lines are scribed in the paintonly and are not cut into the metal. Fillthe scribed lines with white paint andwipe off the excess. If conditions preventbore sighting with the tube level, longi-tudinal compensation for an unlevel(elevated or depressed) tube may bemade by matching the scribed lines (and ® of figure 30. If the trunnionscannot be leveled, cross-level compensa-
92 AGO 4316C
Figure 30. Soribed lines.
tion may be made by matching scribedlines © and ( of figure 30.
56. Conditioning
The on-carriage sighting equipment of theweapon is in correct adjustment when the follow-ing conditions exist:
a. 'Mounts and instruments are securely at-tached and there is no binding or excessive back-lash between gears.
b. The line of sight of the panoramic telescopeis parallel to the axis of the bore.
c. When the trunnions are level the line of sightof the panoramic telescope remains in a plane
AGO 4316C 93
parallel to the vertical plane passing through theaxis of the bore as the tube is elevated through-out its limits of elevation or depression.
d. All bubbles are level when the weapon isleveled both laterally and longitudinally and allscales and indexes read zero except the angleof sight scale which reads 300.
57. Testing Target Method
This method consists of making the line of sightof on-carriage fire control equipment parallel to,the axis of the tube using the aiming diagramsof the testing target as aiming points.
Caution: For weapons modified per MWO ORDC21-W19, i.e., a bracket added to raise the sight.8 inches, test target 1-T-283-42 is not correct andmust have an additional diagram improvisedabove the sight diagram.The steps to be followed are-
a. Trunnions. Level the trunnions as exactlyas possible (par. 55).
b. Tube. Using the gunner's quadrant, levelthe tube.
c. Bore Sights. Place the breech and muzzlebore sights in their proper positions.
d. Test Target Alinement. Without movingthe gun (except for elevating and depressingslightly when using testing target reference lines)aline the center testing diagram with the lineof sight through the tube (fig. 31). The target.normally should be located at least 50 yards infront of the muzzle.
94 AGO 4316C.
Figure 31. Alining the testing target.
e. Cant Compensation. If the trunnions arelevel, level the target by means of a plumb line(fig. 29). If the trunnions are not level, cant thetarget to correspond to the cant of the trunnions.In either case the face of the target is perpen-dicular to the axis of the bore.
f. Panoramic Telescope Lateral Alinement. Itis assumed that all lost motion has been eliminated(par. 42) and that the cross-level bubble is in
AGO 4316C 95
adjustment (par. 63c). Level and zero the sightas in paragraph 22b. As both the azimuth scaleand the slipping azimuth scales are set at zero,the door may be either open or closed. If thevertical hair of the reticle is not in alinement withits aiming diagram, loosen the tangent lockingscrews (fig. 32) and adjust the tangent screws(fig. 33) until the vertical hair is properly alined,
Figure 32. Loosening a tangent locking screw.
96 AGO 4316C
making sure that the panoramic telescope fitssnugly against the tangent screws without bind-ing. Tighten the locking screws and verify theadjustment.
g. Panoramic Telescope Horizontal Alinement.If the horizontal hair of the reticle is out of aline-ment, turn the elevation knob of the telescope untilit is alined properly. Loosen the clamping screws(fig. 34) and shift the scale into coincidence withthe fixed index (fig. 35). Tighten the lockingscrews and verify the adjustment.
h. Elevation Index. Loosen the elevation indexlocking screws. Slip the movable index until it
Figure 33. Adjusting the vertical reticle with, thetangent screws.
AGO 4316C 97
Figure 34. Loosening the clamping screws.
coincides with the fixed index (fig. 36). Tightenthe screws and verify the adjustment.'
i. Elevation (Range) Quadrant. Verify thatthe locking screws of the elevation micrometer aretight. With the line of sight through the tubestill on the appropriate aiming diagram and withthe elevation scale near or on zero, set the eleva-tion micrometer scale at zero. Level the longi-
98 AGO 4316C
Figure 35. Shifting zero of the elevation knob to its index.
Figure 36. Shifting elevation index into coincidence.
tudinal- and cross-level bubbles of the range quad-rant with the angle of site micrometer and thecross-leveling worm knob.
j. Elevation Scale Index. If the elevation scaleindex does not coincide exactly with zero, loosenthe screws holding the index plate and slide
AGO 4316C 99
Figure 37. Shifting elevation scale index to zero.
the plate to zero (fig. 37). Tighten the screwsand verify the adjustment.
k. Angle of Site Scale. If the angle of site scaledoes not read 3(300), loosen the two lockingscrews of the scale and slip the scale until thenumeral 3 is in coincidence with the index (fig.38). Tighten the screws and verify the adjust-ment.
1. Angle of Site Micrometer. If the angle of sitemicrometer does not read zero, loosen the clamp-ing screw in the micrometer knob and slip thescale to zero (fig. 39). Be sure that the knob doesnot turn, thus throwing the bubble off center.Tighten the locking screw and verify the adjust-ment.
m. Elbow Telescope.(1) M23 mount. No deflection adjustment
can be made. If the zero range line ofthe elbow telescope does not match the
100 AGO 43160
Figure 38. Shifting angle of site scale to 3 (300).
Figure 39. Adjusting angle of site micrometer scaleto zero.
AGO 4316C 101
horizontal line of its aiming diagram,loosen the worm clamping bolt. With ascrewdriver bring the zero line intoalinement with the horizontal line on theaiming diagram. Tighten the wormclamping bolt and verify the adjustment.If the horizontal reticle is not parallel tothe horizontal line of its diagram, bringit into alinement by turning the bracketrotating knob.
(2) M42 mount. There is no provision forleveling the reticle lines. If the verticalreticle is not in alinement, loosen the jamnut on the lateral adjusting screw and,with a screwdriver, turn the lateral ad-justing screw to aline the reticle. Tightenthe jam nut and verify the adjustment.If the horizontal reticle is not in aline-ment, loosen the jam nut on the elevationadjusting screw and, with a screwdriverturn the elevation adjusting screw toaline the reticle. Tighten the jam nutand verify the adjustment.
58. Distant Aiming Point Method
This method consists of alining the on-carriagefire control equipment and the line of sightthrough the tube on a common point at least2000 yards from the gun. A distant aiming pointmay be used instead of the testing target if thetesting target is not available or if the tacticalsituation makes its use impracticable. The stepsprescribed for the testing target method (pars.
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57c through 57m) apply except that the boresights and optical sights are alined on the samepoint instead of on the diagrams of the testingtarget. Accurate cross leveling of the trunnionsis unnecessary when bore sighting on a distantaiming point because the lines of sight convergeon a single point. Normally the tube will not belevel, so the scribed lines (par. 55c(3)) will beused.
59. Aiming Circle Method
a. General. The aiming circle method may beused when weather or terrain conditions prohibitthe use of the testing target method or the distantaiming point method. The aiming circle methodcorrects only for deflection errors. It does not in-clude a test for determining elevation errors.When this method is used, any adjustment madeshould be verified at the earliest opportunity bybore sighting with the testing target or distantaiming point. Before bore sighting with the aim-ing circle certain preparatory steps (b below)must be performed, preferably after a basic peri-odic test (pars. 61-64), when the panoramic tele-scope mount is in correct adjustment.
b. Preliminary Operation.(1) To insure accuracy. The greatest care
must be exercised in all phases of theseoperations. All final movements of theinstruments must be made so that thereticles approach the final position fromleft to right to eliminate the effects oflost motion in the gears.
AGO 4816C 103
(2) Parallax. Parallax in the aiming circleand the panoramic telescope must beeliminated. This is done with the aimingcircle, after focusing, by placing infront of the eyepiece lens a dark coloredcardboard or metal parallax shield ofthe same diameter as the eyepiece-lensfocusing sleeve. The shield should havea vertically and horizontally leveled slotone-sixteenth inch wide and one-fourthinch long. It may be held in place witha piece of adhesive tape around the edgeof the focusing sleeve. To eliminateparallax in the panoramic telescope, ashield of the same diameter as the eye-piece-lens housing and having an exactlycentered hole one-sixteenth inch indiameter is mounted in front of theeyepiece lens (fig. 40). A more perman-ent parallax shield may be constructedof brass or bronze shim stock. Whenconstructed of metal a series of fingersapproximately three-sixteenths inchwide and one-fourth inch long separatedby one-fourth inch spaces should extendbeyond the perimeter of the shield.These fingers should be bent along thecircumference of the circle until theyform an angle of 900 with the surfaceof the shield. They serve as a means ofclipping the shield in place quickly andpermit easy removal. Where the eye-piece has a rubber eyeguard, the fingers
104 AGO 4316C
Figure 40. Parallax shield.
permit alinement within the guard with-out its removal.
c. Procedure. Steps to be followed are-(1) Insert the bore sights or improvise sub-
stitutes.(2) Level the trunnions as exactly as possible.
AGO 4316C 105
(3) Sight through the bore sights and alinethe aiming circle in front of the gun ata distance of 30 to 40 yards.
(4) Set up the aiming circle, and with thescales set at zero, sight through the axisof the bore.
(5) Sight through the axis of the bore, andwith the elevating and traversing mech-oanism, aline exactly the line of sightthrough the bore on the objective lensof the aiming circle.
(6) Recheck to insure that at zero setting theline of sight through the aiming circleis directly through the axis of the bore.
(7) Level panoramic telescope mount bubblesand point objective lens toward the aim-ing circle.
(8) With the upper motion of the aimingcircle turn to the center of the objectivelens of the panoramic telescope and readthe angle.
(9) Set the angle from the aiming circle ((8)above) on the azimuth micrometer scaleof the panoramic, telescope.
(10) Adjust the tangent screws until the ver-tical hair of the telescope is exactly onthe center of the objective lens of theaiming circle. Recheck the angle settingsand the alinement of the vertical hairs.
60. Standard Angle Method
a. General. Conditions may exist when the boresighting methods previously described are imprac-
106 AGO 4816C
ticable. Under such circumstances the alinementof the optical axis of the panoramic telescope par-allel to the axis of the bore may be tested andadjusted by referring to a selected point on themuzzle. The deflection and elevation angles neces-sary to refer the line of sight of the telescope tothe selected point on the muzzle are referred to asthe standard angles. Once the standard hori-zontal and vertical angles have been determined,they may be used for a quick test of the alinementof the panoramic telescope when more precisemethods cannot be used. Misalinement discoveredand corrected as a result of this test should beverified by a more accurate method at the earliestopportunity. When using the standard anglemethod of bore sighting, be sure that the positionof the recoiling parts with respect to the nonre-coiling parts is the same as when the standardangles were determined. Because of this, the re-coil system must be checked to see that it containsthe proper amount of recoil oil before determiningthe standard angles.
b. Preliminary Operations. The procedure fordetermining standard angles is as follows:
(1) With the tube in battery, scribe lines inthe paint to mark the position of partswhich move in recoil with respect toparts which do not move in recoil (fig.41).
(2) Carefully level the trunnions.(3) Bore sight the gun using a testing target.(4) With adhesive tape fasten a bright com-
mon pin in the left horizontal witness
AGO 48160 107
Figure 41. Scribing line to mark normal position ofrecoiling parts.
mark. Allow the pin to project to theleft of the muzzle (fig. 42).
(5) Fasten the telescope parallax shield inplace over the eyepiece (fig. 40).
(6) Verify that the elevation index and mi-crometer on the telescope are at zero.
108 AGO 4816C
4--
IC - ' -
Figure 42. Sight picture of projecting pin.
(7) Elevate the tube until it is approximatelylevel with the top of the panoramictelescope.
(8) Level the bubbles of the telescope mountand refer the telescope to the junctionof the pin with the muzzle. Adjust thetube elevation and turn the azimuth mi-crometer knob until; with the bubbleslevel, the horizontal and vertical hairsof the telescope are exactly on the junc-tion of the pin with the muzzle (fig. 42).
(9) Read the angle from the panoramic tele-scope to the nearest one-fourth mil. Sincethe graduations are to the nearest mil it
AGO 4316C 109
is necessary to interpolate to the nearestone-fourth mil. This is the standard azi-muth (horizontal) angle for the guntested.
(10) With either the range quadrant or gun-ner's quadrant measure the elevation ofthe tube to the nearest one-fourth mil.This is the standard elevation (vertical)angle for the gun tested.
(11) With a knife blade or other sharp metalpoint scribe lines in the paint on the fol-lowing parts:
(a) Straight across the junction of thecross-leveling segment and the cross-leveling worm housing.
(b) Straight across the junction of thecross-leveling worm housing and thecross-leveling worm knob shaft.
(c) Straight across the junction of therocker and the actuating arm.
(d) Straight across the junction of the ele-vation knob shaft and the bracket.
(12) Fill the scribed lines with red paint andwipe off the excess.
c. Procedure. Once the standard angles havebeen determined, steps in performing the stand-ard-angle method of bore sighting are as follows:
(1) Verify that the parts that move in recoilare in the same position with respect tothe nonrecoiling parts as they were whenthe standard angles were determined.
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(2) Verify that the trunnions are canted notmore than 10 mils; if convenient, levelthe trunnions.
(3) With adhesive tape fasten a pin in theleft horizontal witness mark so that thepin projects out to the left of the muzzle.
(4) Using the range quadrant or gunner'squadrant elevate the tube to the standardelevation angle.
(5) Place the parallax shield on the eyepieceof the telescope.
(6) Set the standard azimuth angle on thepanoramic telescope. Make sure that thered scribe lines are in coincidence.
(7) If the vertical reticle is not exactly onthe junction of the pin and the muzzle,adjust the tangent screws until the ver-tical reticle is properly alined.
(8) If the horizontal reticle is not exactly onthe junction of the pin and the muzzle,turn the elevating knob of the panoramictelescope until it is properly alined. Ad-just the zero of the elevation knob scaleso that it is in alinement with the index.
Section IIIl. BASIC PERIODIC TEST
61. General
Basic periodic tests are performed by the sec-tion under the supervision of the battery executiveand the artillery mechanic. These tests are per-formed at the discretion of the unit commander.
AGO 4316C 111
Suggested times for performance are-once eachyear if the gun is used only for nonfiring training;once every 3 months if the gun is fired; as soon aspossible after intensive use, accidents, or travers-ing extremely rough terrain; and whenever thegun fires inaccurately for no readily apparent rea-son. The test reveals whether or not the on-car-riage sighting equipment, the gunner's quadrant,and the fuze setter are in correct adjustment.Preparations for the test include-
a. Bore sight the gun (par. 57).b. Place the motor carriage on a site that is
as near level as possible.
c. Accurately level the trunnions, using jacksif necessary. Check the leveling by tracking aplumb line with the bore sights of the tube. Theplumb line (par. 55c (1)) should be suspendedapproximately 5 feet in front of the muzzle andshould be long enough to permit, if possible, maxi-mum elevation of the tube while tracking theplumb line. The trunnions are level when the tubetracks the entire length of the plumb line withoutdeviating more than the thickness of the muzzlebore sight cord. Check this setting frequently asthe following tests are dependent on the trunnionsbeing accurately leveled at all times.
62. Test of Gunner's Quadrant
a. General. The gunner's quadrant must be inproper adjustment before conducting tests andadjustments of other sighting and fire controlequipment. Inspect the shoes of the gunner's quad-
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rant for dirt, nicks, or burrs. Similarly, inspectthe leveling plates on the upper surface of thebreech ring. Dirt, nicks, or burrs on these sur-faces will cause the instrument to give inaccuratereadings.
b. End-for-End Test.
(1) Set both the index arm and micrometerscale of the gunner's quadrant at zero,making sure the auxiliary indexes match.
(2) Place the quadrant on the leveling platesof the breech, the line of fire arrow point-ing toward the muzzle, and center thequadrant bubble by turning the elevat-ing handwheel.
(3) Reverse the quadrant on the levelingplates (turn it end-for-end). If the bub-ble recenters, the quadrant is in adjust-ment and the test is completed.
(4) If the bubble does not recenter, try tocenter it by turning the micrometer knob.
(a) If the bubble centers, read the blackfigures and divide by two. This is thecorrection.
(b) Place the correction on the micrometerand level the tube using the elevationhandwheel.
(c) Check by again reversing the quad-rant. The bubble should center.
(5) If the bubble does not center as in (4)above, move the arc down one gradua-tion (10 mils).
AGO 4316C 113
(a) Turn the micrometer until bubblecenters.
(b) Take the reading on micrometer, add10 to it, and divide the sum by 2. Thisis the correction.
(c) Place this reading on the micrometerleaving the arm at minus 10; level thetube with the elevation handwheel.
(d) Check by reversing the quadrant onthe plates. The bubble should center.
(e) The quadrant should be sent to an ord-nance unit if the correction of erroramounts to more than plus or minus0.4 mil.
c. Micrometer Test.(1) Set the index arm to read 10 mils on the
graduated arc and set the micrometerscale at zero.
(2) Place the quadrant on the leveling plateson the breech ring, the line-of-fire arrowpointing toward the muzzle, and centerthe quadrant bubble by elevating thetube.
(3) Set the index arm at zero on the gradu-ated arc and turn the micrometer onerevolution to read 10 mils.
(4) Reseat the quadrant on the levelingplates. The bubble should center.
Caution: Do not disturb the laying ofthe tube.
(5) If the bubble does not center, the microm-eter is in error and must be adjusted byordnance personnel.
114 AGO 48160
d. Comparison Test. Compare readings takenat low, medium, and high elevations with all ofthe gunner's quadrants of a battery on a singlegun whose quadrant seats have been accuratelycross leveled. Any quadrant differing from theaverage by more than 0.4 mil at any elevationshould be sent to ordnance for adjustment.
e. Correction. When a gunner's quadrant re-quires a correction as determined by the end-for-end test, this correction is not carried during fir-ing but is applied only when making sight testsand adjustments.
63. Test of Telescope Mount
a. General. The purpose of this test is to deter-mine whether the azimuth compensating mechan-ism of the telescope mount actually transmits themotion of the tube to the sight mount so that anydeviation in deflection due to elevating the tube iscorrected throughout all elevations. It checks theadjustment and mounting of the telescope mount,the setting of the cross-level and longitudinal-levelvials, and the alinement of the telescope socket.Test b (below) may be performed with the trun-nions either level or canted. It reflects total errorsof the entire mechanism. Because compensatingerrors of various parts of the mount may resultin the weapon testing out properly with test b,the other tests specified in c through e should beperformed regardless of the result of test b. Totalerrors found in test b may then be narrowed downto errors in specific parts.
AGO 4316C 115
b. General Test.(1) Bore sight the weapon.(2) Make trunnions as level as possible.(3) With bore as near zero elevation as pos-
sible sight through the bore on plumbline.
(4) Level mount bubbles and refer to aclearly defined distant aiming point nearthe front or rear.
(5) Elevate the tube to limits of plumb line,or maximum elevation, in 100-mil steps.At each step-
(a) Traverse if necessary to bring the lineof sight through the bore to the plumbline.
(b) Level mount bubbles.(c) Note deviation of optical axis of sight
from the aiming point.(6) Deflection deviation is measured on the
azimuth micrometer scale-allowabledeviation, 1 mil.
(7) Horizontal deviation is measured withthe longitudinal-level bubble-allowabledeviation, 1-vial graduation.
c. Basic Test for the Range Quadrant.(1) Cross-level test.
(a) Center the cross-level bubble.(b) Turn the elevation knob throughout
its limits of motion.(c) The cross-level bubble should remain
centered within one-half vial gradua-tion.
116 AGO 4316C
(2) Pivot azimuth alinement test.(a) Center the previously tested cross-level
bubble.(b) Elevate and depress the tube, checking
to see that the vertical muzzle hairtracks the plumb line, and watch thecross-level bubble.
(c) The cross-level bubble should remaincentered within one-half vial gradua-tion.
(3) Pivot vertical alinement test.(a) Relevel the tube using the tested gun-
ner's quadrant.(b) Center the longitudinal-level bubble by
turning the angle of site micrometerknob.
(c) Operate the cross-level knob through-out its limits of motion.
(d) The longitudinal-level bubble shouldremain centered within one-half vialgraduation.
(4) Angle of site test.(a) Recheck level of the tube with the
tested gunner's quadrant.(b) Cross level the range quadrant and set
the elevation scale and elevation mi-crometer at zero.
(c) Center the longitudinal-level bubble byturning the angle of site micrometerknob.
(d) Set angle of site scale to read 3(300)and the angle of site micrometer toread zero.
AGO 4316C 117
(5) Comparison test.(a) Compare the readings indicated by the
tested gunner's quadrant with thoseof the range quadrant at low, medium,and high elevation of the tube.
(b) The two instruments should agree atall elevations checked.
d. Basic Test for the Panoramic TelescopeMount, and Panoramic Telescope.
(1) Cross-level test.(a) Center the cross-level bubble.(b) Turn the elevation knob throughout
its limits of motion.(c) The cross-level bubble should remain
centered within one-half vial gradua-tion.
(2) Pivot alinement test.(a) Center the cross-level bubble and place
the line of sight of the panoramic tele-scope on a sharply defined aimingpoint. (Plumb line may be used.)
(b) Elevate the tube to maximum elevationwhile keeping the telescope mount levellongitudinally.
Note. Do not readjust the cross-levelbubble after initial setting.
(c) Check at low, medium, and high eleva-tions of the tube. The line of site of thepanoramic telescope should not deviatemore than 1 mil and the cross-levelbubble should remain centered withinone-half vial graduation.
118 AGO 4316C
(3) Vertical alinement test of telescopemount.
(a) Relevel the tube using the gunner'squadrant.
(b) Center the longitudinal-level bubble.(c) Operate the cross-leveling knob
throughout its limits of motion. Thelongitudinal-level bubble should re-main centered within one-half vialgraduation.
(4) Basic test for the panoramic telescope.(a) Zero the scales on the panoramic tele-
scope.(b) Traverse and elevate the tube as neces-
sary to place the panoramic telescopereticle cross hairs on an aiming point.
(c) Rotate the telescope head through acomplete circle (6400 mils). The tele-scope cross hairs should return to theaiming point within 1 mil.
(d) Rotate the telescope head through acomplete circle in the opposite direc-tion. The telescope cross hairs shouldagain return to the aiming point towithin 1 mil.
(5) Telescope mount socket alinement test.(a) Center the cross-level bubble.(b) With the panoramic telescope scales
set at zero, traverse the tube until thevertical hair of the telescope reticle ison the plumb line with both the cross-level and longitudinal-level bubblescentered.
AGO 4816C0 119
(c) Sight through the telescope and rotatethe elevation micrometer knobthroughout its limits of motion. Thevertical hair should remain on theplumb line within 1 mil.
(d) Set the panoramic telescope scales at1600 mils, and shift the trails until thevertical hair is on the plumb line withboth the cross-level and longitudinal-level bubbles centered.
(e) Rotate the telescope elevation microm-eter knob throughout its limits of mo-tion. The vertical hair should remainon the plumb line within 1 mil.
(6) Allowable errors. If the range quadrant,telescope mount, or panoramic telescopeexceeds the tolerance authorized on anyof the tests outlined, the howitzer and/orpanoramic telescope should be sent toordnance for adjustment.
64. Fuze Setters
a. General. Examine the stop which fits intothe slot in the movable time ring and the adjust-ing pawl which engages the notch in the fixed fuzering to see that their edges are not burred or bent.,Depress the adjustable pawl against its spring tosee that the movement of the pawl is free. In thefollowing tests be sure to test the fuze setter withthe fuze for which it is designed; the time scaleon the fuze setter must have the same graduationsas the time ring on the fuze.
120 AGO 4316C
b. Time Scale Test. Set the corrector to 30, ifan M22 or M23, and set any convenient time onthe time scale. Test the time scale of the fuze set-ter by setting several fuzes.
Caution: Before setting a fuze, make sure thatthe T and C screws (if applicable) of the fuze set-ter are tight to prevent any slipping of the scaleindexes when the handle of the fuze setter isrotated.The time set on the fuze should agree with thetime setting on the fuze setter within one-fourthof the smallest graduation on the fuze time ring.The tolerance amounts to 0.05 second for fuzeshaving 0.2-second graduations, and 0.125 secondfor fuzes having 0.5-second graduations. If thefuzes set do not agree with the time set on thefuze setter, repeat the test as a check with a dif-ferent setting. If the fuzes set still do not agreewith the fuze setter, refer the instrument to anordnance unit for adjustment.
Caution: Do not set any one live fuze more thantwice. The fuze from a dud must never be used.Reset all fuzes to SAFE and replace the safetywire or cotter pin.
65. Ordnance Check
It is not contemplated that using units will havethe necessary facilities, tools, or skilled mechanicsto perform the more precise tests and adjustmentsof sighting and fire control equipment. When defi-ciencies recur or. when defects cannot be correctedin the field, ordnance checks should be scheduled.
AGO 4316C 121
CHAPTER 8
MAINTENANCE AND INSPECTIONS
66. General
Maintenance and inspection is essential to in-sure that the section is prepared to carry out itsmission immediately. Systematic maintenance andinspection drills provide the best insurance againstunexpected breakdown at the critical momentwhen maximum performance is essential.
67. Disassembly, Adjustment, and Assembly
Disassemblies and adjustments of the weaponauthorized to be performed by battery personnelare prescribed in TM 9-325 and TM 9-749, sup-plemented by instructions contained in Depart-ment of the Army Supply Manuals. No deviationfrom these procedures is permitted unless author-ized by the responsible ordnance officer.
68. Records
a. The principal forms pertaining to the mate-riel are the Artillery Gun Book (00 Form 5825),the Field Report of Accidents (SR 385-310-1),and the Unsatisfactory Equipment Report (DAForm 468) (SR 700-45-5). Information on thepurpose and use of these forms may be found inthe forms themselves.
122 AGO 4316C
b. The chiefs of sections, battery executive, andbattery commander also should keep semiperma-nent records for information and guidance.
69. Maintenance
For detailed instructions concerning mainte-nance of the 105-mm howitzer M2A1 and M2A2and motor carriage M7B1, (M7B2) see TM 9-325,TM 9-749, and LO 9-749.
70. Inspections
Regular inspections are required to insure thatmateriel is maintained in serviceable condition.
a. The chief of section is responsible for theequipment within his section. He should inspectit thoroughly each day. If he sees the need forrepair or adjustment, he notifies the battery exec-utive immediately so that the necessary actionmay be taken.
b. The executive, accompanied by the artillerymechanic, should make a daily spot check inspec-tion. He inspects different parts of the materieleach day to insure complete coverage every fewdays. At least once a month, the executive makesa thorough mechanical inspection of howitzer, mo.tor carriage, auxiliary equipment, tools, and spareparts.
c. Battery, battalion, and higher commandersshould make frequent command inspections to as-sure themselves that the equipment in their com-mands is being maintained at prescribed stand-ards of appearance, condition, and completeness.
AGO 4316C 123
d. For details on inspecting the 105-mm how-itzer M2A1 and M2A2, see TM 9-325. For detailson inspecting the motor carriage M7B1 and M7B2,see TM 9-749. Deficiencies found during inspec-tions should be remedied promptly.
e. Duties of individuals in performing the nec-essary inspections and maintenance of the how-itzer and carriage are outlined in the followingparagraphs. Work will be made routine, thorough,and rapid by following the drill outlined in theseparagraphs. When the section is reduced instrength, the chief of section must reassign dutiesto insure that all maintenance steps are com-pleted.
71. Duties in Inspection Before Operation (March)
The inspection performed before operation is afinal check on materiel prior to leaving the motorpark for training in the field, the bivouac areafor combat, or before displacement. After inspec-tion, and when all deficiencies have been corrected,the motor carriage, howitzer, and auxiliary arma-ment are ready to go into action. Individual dutiesare as follows:
a. Chief of Section. The chief of section com-mands INSPECT EQUIPMENT.
(1) Supervises inspections by members ofthe section.
(2) Directs gunner to service recoil system.Inspects cylinders for leaks.
(3) Verifies presence of technical manualsand lubrication orders for carriage and
124 AGO 4316C
howitzer, trip ticket, drivers accident re-port form, and gun book.
(4) Inspects ammunition for lot number, con-dition, and stowage.
(5) Inspects loading of section equipment forcompleteness and stowage.
(6) Verifies proper supply of gasoline, oil,water, and emergercy rations.
(7) Inspects and stows individual weaponand personal equipment.
(8) Receives reports of personnel of his sec-tion upon completion of their duties ininspection.
(9) Reports to battery executive when sec-tion personnel have completed their du-ties, "Sir, No. (so-and-so) in order," orreports any defects that the section can-not remedy without delay or assistance.
b. Gunner.(1) Assisted by No. 1, unfastens and folds
back breech end of howitzer cover; in-spects for tears, wear, and broken ormissing fastenings.
(2) Removes panoramic and elbow telescopesfrom case; passes elbow telescope to No.1; insures cleanliness of panoramicsight; seats in mount.
(3) Tests operation of elevating and travers-ing mechanisms.
(4) Bore sights the howitzer. (Bore sight-ing should be checked after displacement
AGO 4316C 125
and prior to firing whenever timepermits.)
(5) When driver is ready to check transmis-sion and final-drive oil level, traversesweapon to right limit to facilitate in-spection.
(6) Tests night-lighting devices.(7) Tests motions of panoramic telescope
mount and inspects leveling devices.(8) Replaces panoramic and elbow telescopes
in case.(9) Services recoil system when so directed
by the chief of section.(10) Moves tube, assisting Nos. 2 and 3 in
locking traveling lock.(11) Assisted by No. 2, verifies presence of
the section tools and spare parts.(12) Assisted by No. 1, replaces and secures
breech end of howitzer cover. Inspectsand stows individual weapon and per-sonal equipment.
(13) Reports, "Gunner ready."
c. No. 1.
(1) Assists gunner unfasten and fold backbreech end of howitzer cover.
(2) Hands vehicle tools to No. 4.(3) Receives elbow telescope from gunner;
secures in mount; assists gunner in boresighting when target is alined; removesand passes to gunner.
126 AGO 4316C
(4) Tests operation of breechblock and firingmechanism.
(5) Inspects breechblock, chamber, and borefor cleanliness, freedom from foreignmatter, and lubrication.
(6) Tests night lighting devices.(7) Uncovers machine gun; inspects gun and
mount; adjusts head space.(8) Inspects machine gun ammunition.(9) Inspects machine gun tools and spare
parts.(10) Inspects and stows individual weapon
and personal equipment.(11) Reports, "No. 1 ready."
d.' No. 2.(1) Assisted by No. 3, removes traveling-lock
bracket.(2) Verifies presence and serviceability of-
(a) Flag set.(b) Hand grenades.(c) Water and rations.(d) First aid kit.(e) Recoil and spare engine oil.(f) Hand fire extinguisher.(g) Decontaminating equipment.(h) Rammer staff.(i) Ample supply of cleaning and preserv-
ing material.(3) Helps gunner inspect the section tools
and spare parts
AGO 4316C 127
(4) Replaces traveling-lock bracket, assistedby No. 3, and engages lock.
(5) Inspects and stows individual weaponand personal equipment.
(6) Reports, "No. 2 ready."
e. No. 3.(1) Assists No. 2 remove traveling-lock
bracket.(2) Inspects fuze setter.(3) Inspects on-carriage ammunition for
proper stowage; assisted by Nos. 4 and5, stows any replenishment ammunition.
(4) Inspects howitzer and mount for looseparts and for broken or cracked welds.
(5) Takes breech cover from edge of car-riage; assists No. 2 replace cover.
(6) Inspects and stows individual weaponand personal equipment.
(7) Reports, "No. 3 ready."
f. No. 4.(1) Removes the muzzle cover and installs
muzzle bore sight.(2) Tests telephone and intrabattery commu-
nication equipment.(3) Assists driver by-
(a) Inspecting under carriage for leaks.(b) Opening engine compartment.(c) Inspecting running engine for leaks.(d) Inspecting lights for proper function-
ing.
128 AGO 4316C
(e) Checking fuel and coolant levels.(f) Inspecting air cleaners and battery.
(4) Inspects track and suspension systemfor-
(a) Loose sprockets and support rollers.(b) Loose track-pin wedge screws.(c) Missing wedges.(d) Worn track-pin bushings.(e) Missing cushion stop rings.(f) Improper track tension.(g) Damaged or badly gouged bogie
wheels.(5) Closes engine compartment.(6) Assisted by No. 5, sets up testing target
when directed by gunner..(7) Removes muzzle bore sight and replaces
muzzle cover.(8) Returns tools to No. 1.(9) Assists No. 3 in stowing ammunition.
(10) Inspects and stows individual weaponand personal equipment.
(11) Reports, "No. 4 ready."g. No. 5.
(1) Verifies presence and serviceability ofaiming posts.
(2) Inspects fixed fire extinguisher and con-trols.
(3) Assists No. 4 in setting up and aliningtest target.
(4) Brings in and stows test target.
AGO 4316C 129
(5) Assists No. 3 in stowing ammunition.(6) Inspects and stows individual weapon
and personal equipment.(7) Reports, "No. 5 ready."
h. Driver.
(1) Inspects ground beneath motor carriagefor evidence of fuel leaks, oil leaks, orcoolant leaks.
(2) Inspects engine and compartment forpresence of fumes and evidence of fuelor oil leaks.
(3) Turns fuel filter handle one complete turnin either direction. (On M4A3 chassischecks coolant level.)
(4) Checks transmission and final drive oillevel.
(5) Mounts and makes visual check of clutchrelease bearing. (Not required on M4A3chassis.)
(6) Turns on main battery switch.(7) Checks fuel supply and gages.(8) Opens inside fuel shutoff valves.(9) Checks engine oil level.
(10) Checks clutch pedal free travel.(11) Sees that gear shift lever latch is operat-
ing and that the lever can be put intoeach position.
(12) Tests action of parking brakes.(13) Tests operation of steering levers.(14) Tests siren switch and fuel cutoff switch.
130 AGO 4316C
(15) Primes engine.(16) Starts and warms up engine.(17) Notes operation of all instruments on
panel.(18) Performs RPM drop check.(19) Checks operation of all lights, assisted
by No. 4.(20) Inspects windshield and protectoscope.(21) Moves motor carriage so entire track
can be inspected by No. 4.(22) Inspects and stows individual weapon
and personal equipment.(23) Reports, "Driver ready."
72. Duties in Inspection During Operation (March)
The inspections performed during operation areconstant checks on the functioning of the motorcarriage and the security of all stowed equipment.The responsibilities and duties of section person-nel are as follows:
a. The chief of section supervises march disci-pline and assists the driver in detecting obstaclesthat would cause injury to personnel or damageto the carriage.
b. The gunner inspects the security of the trav-eling lock, fire control equipment, and gun covers.
c. No. 1 mans the .50 caliber machine gun asdirected by the chief of section.
d. Other numbered cannoneers inspect securityof stowed equipment, ammunition, and trailer and
AGO 431CC 131
act as air sentinels as directed by the chief ofsection.
e. The driver operates the motor carriage andinspects all instruments and controls (TM 9-749).
73. Duties in Inspection During Halt
The inspection at the halt is made to insure thatthe motor carriage and armament are in satis-factory operational condition. The halt providesthe section an opportunity to inspect for mal-functions that could not be detected during opera-tion. The duties of the members are as follows:
a. Chief of Section. The chief of section com-mands PERFORM HALT INSPECTION.
(1) Inspects general condition of motor car-riage and armament.
(2) Supervises inspection by members of thesection.
(3) Makes general check of tracks, sprockets,and suspension system; checks beneathvehicle for leaks.
(4) Receives report of section members.(5) Reports to the battery executive when in-
spection is completed, "Sir, No. (so-and-so) in order," or reports any defects thatthe section cannot remedy without delay.
b. Gunner.(1) Removes muzzle cover. If dirt has accu-
mulated in tube, instructs N'o. 3 to swabbore.
(2) Bore sights howitzer if time permits; re-places muzzle cover.
(3) Reports, "Gunner ready."
132 AGO 4316C
c. No. 1.(1) Checks .50 caliber machine gun and am-
munition.(2) Bore sights elbow telescope if time per-
mits.(3) Acts as air sentinel as directed by chief
'of section.(4) Reports, "No. 1 ready."
d. No. 2.(1) Removes and replaces firing lock, or in-
stalls and removes rear bore sight, ifrequired.
(2) Checks transfer unit, differential, andfinal drives for evidence of overheating.
(3) Reports, "No. 2 ready."e. No. 3.
(1) Inspects 105-mm ammunition in carriagefor security and ready accessibility.
(2) Checks coolant level, replenishing if nec-essary.
(3) Reports, "No. 3 ready."f. No. 4.
(1) Opens engine compartment and inspectsfor cleanliness and leaks.
(2) Inspects air cleaners for security andcleanliness.
(3) Closes engine compartment.(4) Reports, "No. 4 ready.'"
g. No. 5.(1) Inspects suspension system for loose
parts and evidence of overheating.
AGO 4316C 133
(2) Removes rocks and mud from tracks andsuspension system.
(3) Reports, "No. 5 ready."h. Driver (TM 9-749).
(1) Idles engines at 800 rpm 3 to 4 minutes,noting operation of instruments on panel.
(2) Notes operation of engine controls.(3) Inspects protectoscope.(4) Stops engines.(5) Checks fuel and oil levels, replenishing if
necessary.(6) Reports, "Driver ready."
74. Duties in Inspection and Maintenance after Operation
Immediately after operation the motor carriageand howitzer are given whatever servicing andmaintenance needed to prepare them for furthersustained action or to determine the need formaintenance by higher echelons. These operationsmay be performed in the motor park, bivouac area,or combat position. Individual duties of howitzersection personnel are as follows:
a. Chief of Section. The chief of section com-mands INSPECT EQUIPMENT.
(1) Makes general inspection of carriage,trailer, and armament.
(2) Inspects recoil system; services if neces-sary.
(3) Cleans and tests gunner's quadrant.(4) Posts gun book; verifies presence of other
forms and manuals.
134 AGO 4316C
(5) Supervises detailed inspection and main-tenance by cannoneers and driver.
(6) Notifies executive of any requirementsfor personnel, oil and lubricants, am-munition, water and rations, and replace-ment of expendable equipment.
(7) Receives reports of section members.(8) Reports to executive, "Sir, No. (so-and-
so) in order," or reports any defects thatthe section cannot remedy without delayor assistance.
b. Gunner.(1) Tests operation of elevating and travers-
ing mechanisms.(2) Cleans elevating and traversing mechan-
isms.(3) Cleans and inspects coaxial telescope and
mount.(4) Cleans and inspects panoramic telescope
and mount.(5) Bore sights panoramic telescope and
coaxial telescope.(6) Cleans and tests night-lighting devices.(7) Replaces panoramic telescope in case.(8) Assisted by No. 1, inspects howitzer cover
for torn or worn places and for brokenor missing fastenings.
(9) Reports, "Gunner ready," or reports mal-functions.
c. No. 1.(1) Cleans breachblock, assisted by No. 2.
AGO 4316C 135
(2) Assists in cleaning elevating mechanism.(3) Unloads, dismounts, and cleans machine
gun, assisted by No. 2.(4) Reassembles and mounts machine gun,
assisted- by No. 2.(5) Checks status of .50 caliber ammunition.(6) Inspects machine gun tools and spare
parts.(7) Replaces machine gun cover (if in gar-
rison).(8) Tests elevation quadrant with gunner's
quadrant.(9) Cleans and tests night lighting devices.
(10) Cleans and tests firing mechanism.(11) Assists gunner in inspecting howitzer
cover.(12) Reports, "No. 1 ready," or reports any
malfunctions found.
d. No. 2.
(1) Assisted by No. 3, removes travelinglock.
(2) Assembles rammer.(3) Assists No. 1 in cleaning breechblock.(4) Assists No. 1 in cleaning machine gun.(5) Removes firing lock for bore sighting or
places rear bore sight in tube.(6) Inspects the following: flag set, hand
grenades, water and rations, first aidkit, recoil and spare engine oil, handfire extinguisher, decontaminating equip-
136 AGO 4816C
ment, rammer staff, and supply of clean-ing and preserving material.
(7) Replaces firing lock or removes rear boresight.
(8) Assisted by No. 3, replaces traveling lock.(9) Reports, "No. 2 ready," or reports mal-
functions found.e. No. 3.
(1) Assists No.2 in removing traveling lock.(2) Cleans bore of howitzer assisted by Nos.
4 and 5.(3) Refills ammunition racks assisted by
Nos. 4 and 5.(4) Polices and cleans inside of motor car-
riage.(5) Assists No. 2 in replacing traveling lock.(6) Reports, "No. 3 ready."
f. No. 4.(1) Removes muzzle cover and installs muzzle
bore sight.(2) Assisted by No. 5, sets out test target if
directed.(3) Tests telephone and communication
equipment.(4) Assists No. 3 clean bore.(5) Assists No. 3 refill ammunition racks.(6) Opens engine compartment.(7) Inspects running engine for loose parts,
excessive vibration, and leaks.(8) Inspects under carriage for evidence of
leaks.
AGO 4316C 137
(9) Assists driver in checking lights, clean-ing suspension system and outside of car-riage, and replenishing fuel, oil, andcoolant.
(10) Services air cleaners.(11) Inspects fixed fire extinguisher and con-
trols.(12) Closes engine compartment.(13) Removes muzzle bore sight and replaces
muzzle cover.(14) Reports, "No. 4 ready," or reports mal-
functions found.
g. No. 5.(1) Inspects and lubricates track and sus-
pension systems.(2) Assists No. 4 set out test target.(3) Assists No. 3 clean bore of howitzer.(4) Assists No. 3 refill ammunition racks.(5) Brings in test target.(6) Assists driver clean suspension system
·and outside of carriage.(7) Reports, "No. 5 ready," or reports ir-
regularities found.
h. Driver (TM 9-749).(1) Idles engines 3 to 4 minutes before stop-
ping.(2) Notes engine operation and inspects in-
struments.(3) Stops engines and closes fuel shutoff
valves.
138 AGO 4316C
(4) Inspects the following: steering levers,selector and shift levers, siren, lights,periscope and heads, hatch hood, inter-phone equipment, and for evidence ofleaks in the driver's compartment.
(5) Verifies presence of lubrication orderand other required forms.
(6) Inspects oil levels in-differential, finaldrive, transfer unit, engine, and trans-mission; replenishes if necessary.
(7) Inspects coolant level; replenishes ifnecessary.
(8) Cleans suspension system and outside ofcarriage, assisted by Nos. 4 and 5.
(9) Reports requirements for fuel, lubricants,and maintenance.
(10) Reports, "Driver ready," or reports mal-functions found.
75. Duties in Weekly Inspection and Maintenance
In garrison these services are performed weeklywhether the material is used or not. On maneu-vers or in combat they are performed after eachfield operation. Individual duties are as follows:
a. Chief of Section. The chief of section com-mands PERFORM PERIODIC INSPECTION.
(1) Inspects general condition of carriage.Observes ground under vehicle for leaks.
(2) Supervises inspection; coordinates workof crew.
(3) Directs weekly lubrication, referring tolubrication orders.
AGO 4316C 139
(4) Receives reports of section members.(5) Reports to executive, "Sir, No. (so-and-
so) in order," or reports any defectsthat the section cannot remedy withoutdelay or assistance.
b. Gunner.
(1) Inspects and cleans sighting equipment,sight mounts, and instruments.
(2) Assisted by No. 1, checks and cleans ele-vating and traversing mechanisms.
(3) Performs lubrication, with particularemphasis on howitzer and mount.
(4) Reports, "Gunner ready."c. No. 1.
(1) Inspects and cleans firing mechanism.(2) Inspects and cleans .50 caliber machine
gun and mount.(3) Assists gunner in checking and cleaning
elevating and traversing mechanisms.(4) Cleans right forward section of carriage.(5) Passes vehicular tools to No. 4.(6) Assists as directed in performing weekly
lubrication.(7) Reports, "No. 1 ready."
d. No. 2.(1) Tightens loose bolts, nuts, and connec-
tions in hull interior.(2) Cleans right rear section of carriage.(3) Performs maintenance on batteries.
140 AGO 4816C
(4) Assists as directed in performing weeklylubrication.
(5) Reports, "No. 2 ready."e. No. 8.
(1) Cleans left forward section of carriage.(2) Inspects ammunition clamps for condi-
dition and security.(3) Inspects left track and suspension
system.(4) Tightens loose bolts and connections out-
side carriage on left side.(5) Assists as directed in performing weekly
lubrication.(6) Reports," No. 3 ready."
f. No. 4.(1) Cleans left rear of carriage.(2) Receives vehicular tools froinm No. 1; in-
spects and cleans tools prior to return-ing them to No. 1.
(3) Inspects right track and suspensionsystem.
(4) Tightens loose bolts and connections out-side carriage on right side.
(5) Assists as directed in performing weeklylubrication.
(6) Reports, "No. 3 ready."
g. No. 5.(1) Cleans outside of carriage.(2) Touches up rust spots on carriage and
howitzer.
AGO 4316C 141
(3) Assists as directed in performing weeklylubrication.
(4) Reports, "No. 5 ready."h. Driver.
(1) Cleans and inspects driver's compart--ment; tightens nuts, bolts, and connec-tions.
(2) Inspects instruments, electrical wiring,and connections.
(3) Cleans engines, engine compartment;cleans carburetor fuel screens.
(4) Performs lubrication, with particularemphasis on motor carriage.
(5) Reports, "Driver ready."
AGO 4310C
CHAPTER 9
DECONTAMINATION OF EQUIPMENT
76. General
Equipment which has been contaminated bychemical, biological, or radiological agents con-stitutes a danger to personnel. Contaminationmeans the spreading of an injurious agent in anyform and by any means. Persons, objects, or ter-rain may be contaminated. Decontamination isthe process of making any contaminated placeor thing safe for unprotected personnel. Thiscan be done by covering, removing, destroying, orchanging into harmless substances the contami-nating agent or agents. Generally, only equip-ment contaminated by persistent agents need bedecontaminated.
77. Decontamination for Chemical Agents
a. Ammunition. With rags, wipe off visible con-tamination from projectiles. Apply DANC (de-contamination agent, noncorrosive, M4), wipewith gasoline-soaked rag, then dry. If DANC isnot available, scrub with soap and cool water.Slurry (equal weights of water and chloride oflime) can be used on contaminated ammunitioncontainers, but it must not be allowed to penetrateto the ammunition itself.
AGO 4316C 143
b. Instruments. If exposed to corrosive gases,clean instruments as soon as possible with alcohol(or gasoline, if no alcohol is available), and applya thin coat of light machine oil. A rag dampenedwith DANC may be used, followed by drying witha clean rag and then applying a coat of machineoil. DANC injures plastic or hard rubber surfaces.surfaces.
c. Weapons. Remove dirt, dust, grease, and oil.Do not apply wet mix but allow surfaces to airafter soil and dirt have been removed. DANCcan be used on all metal surfaces except the bore.Also effective on metal are hot water, cleaningsolvent, or repeated application of gasoline onswabs. If the emergency use, of gasoline-soakedswabs is made (FM 21-40), extreme care must:be taken to insure that the gasoline does notspread the contamination and that no gasoline inliquid or vapor form remains. This excess wouldbe ignited when the gun is fired. After decon-tamination, weapons are dried and oiled.
d. Automotive Equipment. Exposure to the aircan neutralize light contamination from spray..For heavier contamination use DANC on interioror exterior surfaces which personnel are likely-to touch. For larger area decontamination, washvehicle with water and scrub painted surfaces.with soap and water.
78. Decontamination for Biological and RadiologicalAgents
a. General. After a contaminating attack, re-covery of equipment may be achieved either by-
144 AGO 4316C;
waiting, to permit the decay of contamination, orby active decontamination to reduce danger to alevel where it is no longer a significant hazard tooperating personnel. Decontamination may beeither rough or detailed, depending on the urgencyof the military situation. The procedure adoptedwill be a command decision.
b. Rough Decontamination. Rough decontami-nation is performed when urgency is the mainfactor. Its purpose is to reduce contaminationsufficiently to permit personnel to work with, orclsoe to, equipment for limited periods. IRough de-contamination may be achieved by means of wateror steam if available. Soap or other detergentused in conjunction with water or steam aids indecontamination.
c. Detailed Decontamination. Detailed decon-tamination, in which the emphasis is on thorough-ness, will be carried out in rear areas and repairbases and includes procedures of surface decon-tamination, aging and sealing, and disposal.
79. References
For further information on decontamination,see FM 21-40, TM 3-220, and TF 3-1407.
AGO 4316C 145
-CHAPTER 10
DESTRUCTION OF EQUIPMENT
80. Generala. Tactical situations may arise in which it is
necessary to abandon equipment in the combatzone. In such a situation all abandoned equip-ment must be destroyed to prevent its use by theenemy.
b. The destruction of equipment subject to cap-ture or abandonment in the combat zone will beundertaken only upon authority delegated by adivision or higher commander.
c. All batteries will prepare plans for destroy-ing their equipment in order to reduce the timerequired should destruction become necessary.The principles to be followed are-
(1) Plans for destruction of equipment mustbe adequate, uniform, and easily carriedout in the field.
(2) Destruction must be as complete as theavailable time, equipment, and personnelwill permit. Since complete destructionrequires considerable time, prioritiesmust' be established so that the moreessential parts are destroyed first.
(3) The same essential parts must be de-stroyed on all like units to prevent the
146 AGO 4316C
enemy from constructing a complete unitfrom damaged ones.
(4) Spare parts and-accessories must begiven the same priorities as the partsinstalled on the equipment.
81. Methods
To destroy equipment adequately and uniformlyall personnel of the unit must know the planand priority of destruction and be trained in themethods of destruction.
82. References
For detailed information on destruction of the105-mm howitzer, fire control equipment, andmotor carriage, see TM 9-325 and TM 9-731E;for destruction of ammunition, see TM 9-1901.
AGO 4316C 147
CHAPTER 11
SAFETY PRECAUTIONS
83. General
Safety precautions to be observed in trainingare prescribed in SR 385-310-1. Additional in-formation is found in FM 6-140, TM 9-325,TM 9-749, TM 9-1900, and TM 9-1901. The moreimportant safety precautions are summarized inthefollowing paragraphs.
84. Ammunition
a. All ammunition on the ground at the firingposition must be so placed that it is protectedagainst explosion in case of accident at the posi-tion. Flames and explosive materials such asgasoline must be kept away from ammunition.Ammunition should be protected from direct raysof the sun by use of a tarpaulin or other suitablecovering.
b. Battery personnel must not attempt to dis-assemble fuzes.
c. If for any reason a round is not fired afterthe time fuze has been set, the fuze must be resetto SAFE before it is restowed.
d. All rounds not fired which have been pre-pared for firing must be checked by the chief ofsection to insure that all seven powder increments
148 AGO 4316C
are present in proper order and condition, andthat they are of the proper lot number. He alsoverifies that the lot number on the ammunitioncorresponds to the lot number on the container.For ammunition that is to be returned to Ord-nance, a battery officer must certify that it hasbeen properly reassembled (FM 6-140).
85. Misfires
a. In the event of a misfire, two more attemptsare made to fire the gun.
Caution: The gun should remain as laid and allpersonnel must stay clear of the muzzle and pathof recoil.All personnel not required for the operation shouldbe cleared from the vicinity.
b. Upon the command to unload (par. 47), theprocedure is as follows:
(1) Open the breech to extract the cartridgecase. Should the complete round be ex-tracted, the projectile is separated fromthe cartridge case.
(2) Inspect the primer in the base of thecartridge case immediately to determine
- whether the indent is normal.(3) Throw the cartridge case clear of all
personnel to prevent injury in case ofa hang-fire.
(4) The projectile is reloaded with anothercartridge case and firing is resumed.
c. See TM 9-325 for action to be taken in casethe indent on the primer is light or if there is no
AGO 4316C 149
indent, indicating that the firing lock is not func-tioning properly.
d. See SR 385-310-1 for safety regulations per-taining to misfires.
86. Drill and Firing
a. The gun is kept unloaded except when firingis imminent.
b. Members of the section on the ground pass inrear of the carriage when going from one sideto another.
c. Personnel should stay a safe distance fromthe breech to prevent injury when the gun recoils.
d. During firing, personnel should use wastein their ears to protect eardrums against injury.
e. In training, there must always be a safetyofficer for each artillery unit firing. For dutiesof the safety officer, see FM 6-40.
AGO 4316C
CHAPTER 12
TRAINING
Section I. GENERAL
87. Purpose and Scope
The purpose of this chapter is to present theabsolute minimum requirements for training thepersonnel of a gun section in the performance oftheir duties in service of the gun. It includesgeneral information on the conduct of training,and tests to be given for the qualification ofgunners.
88. Objectives
The objectives are speed in training cannoneersin their individual duties; and, through drill, toweld them into an effective, coordinated team ableto function efficiently in combat. During training,supervisors may well keep in mind the proficiencysought by Army Training Tests (ATT) 6-1, 6-2,and 6-5. Maximum efficiency is attained throughcontinuous drills.
89. Conduct of Training
a. Training will be conducted in accordancewith the principles set forth in FM 21-5. Its goalshould be the standards set forth in FM 6-125,TM 6-605, SR 615-25-15, and SR 615-25-20.
AGO 4316C 151
b. In general, individual training is conductedby noncommissioned officers as far as practicable.Officers are responsible for training plans, for con-ducting unit training, and for supervising andtesting individual training.
c. Throughout training, the application of priorinstruction to current training must be em-phasized.
d. A record of the training received by eachindividual should be kept. This may be done byeach chief of section keeping a progress cardfor each man in his section. This card shouldshow each period of instruction attended, teststaken, and remarks pertaining to progress.Progress cards should be inspected frequently bythe battery executive to make sure that they arebeing kept properly and to determine the state oftraining. Requiring the chief of section to keepthese records emphasizes his responsibility towardhis section.
e. The necessity for developing leadership andinitiative in noncommissioned officers must be em-phasized constantly throughout training.
90. Standards to be Attained
A satisfactorily trained section must be capableof performing the following functions in thetimes indicated (TM 6-605):
a. Firing 10 rounds (drill ammunition) at dif-ferent deflections, elevations, and time fuze set-tings, using the same charge, in 3 minutes by dayand 4 minutes by night. Changes in data should
152 AGO 4816C
be typical for an area time mission; data is an-nounced from prepared cards.
b. Performing after-firing care and mainte-nance of armament. The gun being in position,clean and lubricate, disassemble and assemble thebreech and firing mechanism, and inspect theweapon, in 30 minutes by day and 40 minutesby night. All tools and materials required shouldbe available at the position.
c. Performing 6-months inspection and mainte-nance of armament. The gun prepared for actionin the gun park, clean and lubricate, as authorized,all parts and assemblies, and prepare for ordnanceinspection in 2 hours. All tools and materialsrequired should be available in the gun park.
d. Each member of the section should know theduties of all other members of the section and beable to perform efficiently in all positions. Seeparagraphs 91-104 for tests to be given for thequalification of gunners.
Section II. TESTS FOR QUALIFICATION OF GUNNERS
91. Purpose and Scope
This section prescribes the tests to be given inthe qualification of gunners. The purposes of thetests are twofold:
a. To provide a means of determining the rela-tive proficiency of the individual artillery soldierin the performance of the duties of the gunner,105-mm howitzer M2 and modifications. The tests
AGO 4816C 153
will not be a basis for determining the relativeproficiency of batteries or higher units.
b. To serve as an adjunct to training.
92. General Instructions
a. Standards of Precision. The candidate willbe required to perform the tests in accordancewith the standards listed below:
(1) Scale settings must be exact and match-ing indexes must be brought into coin-cidence.
(2) Level bubbles must be exactly centered.
(3) The vertical hair in the reticle of thepanoramic telescope must be alined onthe left edge of the aiming post or onexactly the same part of the aiming pointor target each time the gun is laid.
(4) Final motions of azimuth and elevationsetting knobs, as well as traversing andelevating handwheels, must be made inthe appropriate direction. For elevating,the final motion of the handwheel shouldbe in the direction of the more difficultmovement. Final motion for traversingis from left to right. Final movement ofthe vertical hair of the telescope is fromleft to right.
b. Assistance. The candidate will receive no un-authorized assistance. Each candidate may selectauthorized assistants as indicated in the tests. Inthe event a candidate fails any test because of
154 AGO 4316C
the fault of the examiner or any assistant, thetest will be disregarded, and the candidate willbe given another test of the same nature.
c. Time. The time for any test will be the timefrom the last word of the command to the lastword of the candidate's report. The candidatemay begin any test after the first word of thefirst command.
d. Scoring. Scoring will be conducted in ac-cordance with the two subparagraphs Penaltiesand Credit under each subject. If a test is per-formed correctly, credit will be given in accord-ance with the subparagraph Credit under eachsubject. No credit will be allowed if conditionsexist as specified in the subparagraphs headedPenalties.
e. Preparation for Tests. The gun will be pre-pared for action and the candidate posted at theproper position corresponding to the test beingconducted or as indicated in the subparagraphsentitled "Special instructions." The examiner willinsure that the candidate understands the require-ments of each test and will require the candidateto report "I am ready," before each test.
f. Qualification Scores. Minimum scores re-quired for qualification in the courses are asfollows:
Individual classification Points
Expert gunner__ ----------------------------- 90First-class gunner---------------------------- 80Second-class gunner_-------------------------- 70
AGO 4316C 155
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156 AGO 4816C ~·~
94. Direct Laying, Panoramic Telescope
a. Scope of Tests.(1) Four tests (two groups of two tests each)
will be conducted in which the candidatewill be required to execute commandssimilar to those given in c below.
(2) Tests 1 and 2 (and tests 3 and 4) willbe executed as one series of commands.
(3) The candidate will be tested in the dutiesof the gunner, using the one-man, one-sight system.
b. Special Instructions.(1) A stationary target will be placed ap-
proximately 600 yards from the gun.(2) The fixed azimuth scale and micrometer
scale will be set at zero, and indexes ontelescope mount will be matched.
(3) The candidate will be posted as the gun-ner.
(4) The gun will be pointed so that-(a) A shift of approximately 100 miles will
be required for tests 1 and 8.(b) It will not be necessary to shift the
motor carriage for any of the fourtests.
(5) Laying at the termination of tests 1 and3 will not be disturbed prior to beginningtests 2 and 4.
(6) The examiner will announce the assumeddirection of the movement of the targetat the beginning of tests 1 and 3. Theassumed direction of the movement of
AGO 4816C 157
the target in test 3 will be opposite tothat in test 1.
c. Outline of Tests.
Test Examiner commandsnumber (for example) Action of candidate
1 and 3 TARGET, THAT TANK; Traverses tube untilLEAD 5, proper lead hasRANGE 600. been set.
Places proper rangeline of reticle on thecenter of the visiblemass of the target.
Centers cross-levelbubble.
Gives the command,FIRE, when readyand steps clear.
2 and 4 RIGHT (LEFT) 10, ADD Same as test 1 above.(DROP) 200.
d. Penalties. No credit will be allowed if, aftereach test-
(1) The azimuth scale has been moved fromzero.
(2) The indexes on the azimuth micrometerhave been moved from zero.
(3) The indexes on the telescope mount arenot in coincidence.
(4) The lead in mils is not set properly.(5) The proper range line of the reticle is
not on the center of the visible mass ofthe target.
e. Credit.Time in seconds, exactly or less than___ 4 4% 5Credit ______________________________ 2.0 1.5 1.0
158 AGO 4316C
95. Direct Laying, Elbow Telescope
a. Scope of Tests.
(1) Four tests (two groups of two tests each)will be conducted in which the candidatewill be required to execute commandssimilar to those given in c below.
(2) Tests 1 and 2 (and tests 3 and 4) will beexecuted- as one series of commands.
(3) The candidate will be tested in the dutiesof No. 1 cannoneer, using the two-man,two-sight system.
b. Special Instructions.
(1) A stationary target will be placed ap-proximately 600 yards from the gun.
(2) For tests 1 and 3 the field of view of thetelescope will be placed on the target,with the correct range line more than100 yards off the target.
(3) The laying of the gun will not be dis-turbed after tests 1 and 3.
c. Outline of Tests.
Test Examiner commandsnumber (for example) Action of candidate
1 and 3 TARGET, THAT TANK; Places proper reticleRANGE 500. line for announced
range on the centerof the visible massof the target.
Calls, "Set" and stepsclear.
2 and 4 ADD (DROP) 400. Same as test 1 above.
AGO 4316C 159
d. Penalties. No credit will be allowed if, aftereach test-
(1) The correct range line is not on the cen-ter of the visible mass of the target.
(2) The range lines of the reticle are notapproximately horizontal.
Time in seconds, exactly or less than___-- 1 1 2Credit _ …____-- _____-- _-------------- 2.0 1.5 1.0
96. Indirect Laying, Deflection Only
a. Scope of Tests. Eighteen tests will be con-ducted in which the candidate will be required toexecute commands similar to those given below.Tests 1 through 4 (and tests 5 through 9, 10through 13, and 14 through 18) will be executedas one series of commands.
b. Special Instructions.
(1) Commands will not necessitate shiftingcarriage.
(2) The examiner will select a suitable aim--ing point and identify it to the candidate.
(3) Commands for special corrections will begiven only in the tests indicated in theexamples below.
(4) The command for new deflections foreach test will be within the followingprescribed limits:
160 AGO 4316C
Test number Maximum Minimumchange change(mils) (mils)
2 and 11-_______________________ 180 1403 and 12 __-____________________ 90 704 and 13-_______________________ 40 207 and 16-_______________________ 100 608 and 17-- _____________________ 50 309 and 18----____________________ 20 10
(5) The gun will be laid with correct settingsat the conclusion of each test before pro-ceeding with the next test.
(6) Aiming posts will be set out in prescribeddeflection and distances for these tests.
(7) The examIner will designate the sectionnumber of the gun to be used. The exam-iner will announce spec:al correct'ons indeflection to be applied by the candidate.
c. Outline of Tests.
Test Examiner commandsnumber (for example) Action of candidate
1 and SPECIAL CORREC- Sets deflection and ap-10 TIONS, DEFLECTION plies special correc-
2890, NO. 1 LEFT 7 tion.Centers cross- and
longitudinal - levelbubbles.
Traverses tube untilvertical hair is onleft edge of aimingposts.
Checks centering ofbubbles.
AGO 4316C 161
Test Examiner commandsnumber (for example) Action of candidate
Re-lays if necessary.Calls "Ready" and
steps clear.2 and DEFLECTION- 2760 ---- Sets deflection change.
11 Leaves correction ongunner's aid.
Lays on aiming posts.Checks centering of
bubbles.Re-lays if necessary.Calls "Ready" and
steps clear.3 and DEFLECTION 2835 ---- Same as test 2 above.
124 and NO. 1, RIGHT 4____-- ___ Same as test 2 above,
13 but changes gun-ner's aid to right 4and resets deflection2835 opposite index.
At conclusion of test 4 Gunner moves gun-(13) give CEASE ner's aid to zero.FIRE, END OF MIS-SION. (No time con-sidered for this opera-tion.)
5and AIMING POINT, Refers telescope to14 CHURCH STEEPLE, church steeple.
REFER. Reads deflectioi andcalls "No. 1, Deflec-tion (so much)."
6 and DEFLECTION 2800, Slips the slipping azi-15 REFER. muth micrometer
scale to zero.Slips the slipping azi-
muth scale to 2800.
162 AGO 4316C
Test Examiner commandsnumber (for example) Action of candidate
Verifies that verticalreticle is on churchsteeple.
Calls "No. 1, Deflec-tion 2800."
Steps clear.7 and SPECIAL CORREC- Same as test 1 above.
16 TIONS DEFLECTION2920 NO. 1, LEFT 7
8 and DEFLECTION 3040 Same as test 2 above.17
9 and DEFLECTION 3080 Same as test 2 above.18
d. Penalties.
(1) No credit will be allowed if, after eachtest-
(a) The deflection is set incorrectly.
(b) The cross-level or longitudinal-levelbubble is not centered.
(c) The vertical hair of the telescope isnot on the aiming point or left edge ofaiming posts, as the case may be.
(2) No credit will be allowed if the lastmotion of the traverse was not made tothe right.
e. Credit.Time in seconds, exactly or less than-
Tests 1, 10, 6, and 15 each -- _______12 13 14Other tests, each _----------_______ 8 9 10
Credit ----------------------------- ___ 2.0 1.5 1.0
AGO 4816C 163
97. Laying for Elevation with Elevation (Range) Quadrant
a. Scope of Tests. Three tests will be conductedin which the candidate will be required to executecommands similar to those given below.
b. Special Instructions.
(1) Each test will require a change of set-tings and the accompanying laying of thetube in elevation within the followinglimits: Site, 15 to 25 mils; elevation, 20to 40 mils.
(2) Commands for elevation for tests 2 and3 will not be made in multiples of 5 mils.
(3) Special corrections for site will be ap-plied by the candidate.
(4) The candidate will be posted as No. 1cannoneer.
c. Outline of Tests.
Test Examiner commandsnumber (for example) Action of candidate
1 SITE 295, ELEVATION Sets anounced site and280. elevation.
Centers cross-levela n d longitudinal-level bubbles.
Calls "Set" and stepsclear.
2 SITE 320, ELEVATION Same as test 1 above.316.
3 SPECIAL CORREC- Same as test 1 above.TIONS, SITE 310, NO.1 UP 2, ELEVATION323.
164 AGO 4S16C
d. Penalties.(1) No credit will be allowed if, after each
test--(a) The site or elevation is not set accur-
afely.(b) The cross-level or longitudinal-level
bubble is not centered.(2) No credit will be allowed if the last move-
ment of the tube was not in the directionin which it is most difficult to turn theelevating handwheel.
e. Credit.Time in seconds, exactly or less than___-- 6% 7% 8%Credit ------------------------__---- 2.0 1.5 1.0
98. Laying for Elevation with Gunner's Quadrant
a. Scope of Tests. Three tests will be conductedin which the candidate will be required to executecommands similar to those given below.
b. Special Instructions.(1) The gunner's quadrant will be set at zero
for the first test.(2) Each succeeding test will require a
change of quadrant elevation settingwithin the limits of 30 to 60 mils.
(3) The candidate will be posted to the leftof and facing the breech, with the gun-ner's quadrant in his hand.
(4) An assistant, selected by the candidate,will be posted to the right of the breechto operate the elevating handwheel.
AGO 4160 165
c. Outline of Tests.
Test Examiner commandsnumber (for example) Action of candidate
1 QUADRANT 180 ____-- __ Sets quadrant eleva-tion on gunner'squadrant. Seatsquadrant.
Has assistant elevateor depress the tubeuntil the quadrantbubble is centered.
Calls "Ready" andwaits for examinerto verify laying.
2 QUADRANT 240________ Same as test 1 above.3 QUADRANT 205 _______ Same as test 1 above.
d. Penalties.
(1) No credit will be allowed if, after eachtest- -
(a) The quadrant elevation is set incor-.rectly.
(b) The quadrant is not properly seated.
(c) The quadrant bubble is not properlycentered.
(2) No credit will be allowed if the last move-ment of the tube was not in the directionin which it is most difficult to turn theelevating handwheel.
e. Credit.Time in seconds, exactly or less than___-- 6 6% 7Credit ------- _ __________________ 2.0 1.5 1.0
166 AGO 4816C
99. Displacement Correction
a. Scope -of Test. One test, consisting of twoparts, will be conducted in which the candidatewill be required to execute the commands givenbelow.
b. Special Instructions.(1) Aiming posts will be set out at the pre-
scribed distances.(2) An assistant, selected by the candidate,
will be stationed close to the far aimingpost.
(3) The examiner will require the candidateto lay the gun on an announced deflectionand report "I am ready."
(4) The far post or the motor carriage will-then be moved so that a displacement of5 to 10 mils occurs.
(5) The laying of the gun at the terminationof part I will not be disturbed for part II.
c. Outline of Test.(1) Part I.
Examiner commands Action of candidate
CORRECT FOR DISPLACE- Lays the gun so that theMENT. far post appears mid-
way between the nearpost and the verticalcross hair of the tele-scope.
Checks centering of bub-bles.
Re-lays if necessary.Calls "Ready" and steps
clear.
AGO 4316C 167
(2) Part II.
Examiner commands Action of candidate
ALINE AIMING POSTS--...-- Records deflection on shieldand announces "Deflec-tion (so much) re-corded."
Directs assistant in alin-ing aiming posts.
Calls "Ready" and stepsclear.
d. Penalties. No credit will be allowed if-(1) Part I.
(a) The far aiming post does not appearmidway between the near post and thevertical cross hair of the telescope.
(b) The cross-level or longitudinal-levelbubble is not centered.
(c) The last motion of traverse was notmade to the right.
(2) Part II.(a) The deflection is other than the an-
nounced deflection.(b) The aiming posts are not properly
alined.(c) The vertical hair of the telescope is not
on the aiming posts.e. Credit.
Part I, time in seconds, exactly orless than ------__ ----- __---- 3 38 8% 4
Credit ------------------------ 3.0 2.0 1.6 1.0Part II, no time limit--__________Credit ------------------ __-- 1.0 .
168 AGO 4316C
100. Measuring Sight to Mask
a. Scope of Test. One test will be conducted inwhich the candidate will be required to executethe command given below.
b. Special Instructions.
(1) The gun, prepared for action, will beplaced 200 to 400 yards from a mask ofreasonable height.
(2) The tube will be pointed so that it is 100to 150 mils above the crest and 100 to150 mils right or left of the highest pointof the crest.
(3) The candidate will take post at the rightrear of the breech.
c. Outline of Test.
Examiner commands Action of candidate
MEASURE SITE TO MASK_ Sights along lowest ele-ment of bore and oper-ates elevating and tra-versing mechanism untilline of sight just clearscrest.
Sets angle of site scale at300, centers longitudinal-level bubble by turningelevating knob, and cen-ters cross-level bubble.
Reads elevation from ele-vation scale and microm-eter.
Reports "No. (so-and-so),Site to mask (so much)."
AGO 43816C 169
d. Penalties. No credit will be allowed if-(1) The line of sight along the lowest element
of the bore does not just clear crest.(2) The cross-level or longitudinal-level bub-
ble is not properly centered.(3) The angle of site scale does not read 300.(4) The site is announced incorrectly.
e. Credit.Time in seconds, exactly or
less than ---________________11 12 13 14Credit________________________ 4.0 3.0 2.0 1.5
101. Measuring Elevation
a. Sdope of Test. One test will be conducted inwhich the candidate will be required to measurethe elevation by means of the gunner's quadrant.
b. Special Instructions. Prior to the test theexaminer will lay the tube at a selected elevation,measure the elevation, and then set the gunner'squadrant at zero.
c. Outline of Test.
Examiner commands Action of candidate
MEASURE THE ELEVA- Places gunner's quadrantTION. on quadrant seats of the
breech ring.Levels bubble by raising
or lowering the indexarm and turning themicrometer knob.
Announces "No. (so-and-so), Elevation (somuch) ," and hands quad-rant to examiner.
170 AGO 4316C
d. Penalties. No credit will be allowed if-(1) The quadrant bubble is not centered
when the quadrant is seated properly.(2) The elevation is announced incorrectly.
e. Credit.Time in seconds, exactly or less than___-- 8 9% 10%Credit ------------------------------ 4.0 3.0 2.0
102. Measuring Deflection
a. Scope'of Test. One test will be conducted inwhich the candidate will be required to measureand report a deflection in accordance with thecommand given below.
b. Special Instructions.(1) The gun will be laid on aiming posts to
the left front.(2) An aiming point within 200 mils to the
left or right of the aiming posts will bedesignated by the examiner and identi-fied by the candidate.
c. Outline of Test.
Examiner commands Action of candidate
NUMBER (SO-AND-SO), Centers cross-level andAIMING POINT, THAT longitudinal-level bhub-(SO-AND-SO), REFER. ble.
Refers to aiming point.Checks centering of bub-
bles and re-lays tele-scope if necessary.
Reads deflection and re-ports, "No. (so-and-so)deflection (so much)"and steps clear.
AGO 4316C 171171
d. Penalties. No credit will be allowed if-(1) The cross-level or longitudinal-level bub-
ble is not centered properly.(2) The vertical hair of the telescope is not
on the aiming point.(3) The deflection is announced incorrectly.(4) The traversing handwheel is turned.
e. Credit.Time in seconds, exactly or
less than ________________-_ 5 5% 6 6%Credit --__.__________3________ 4.0 3.0 2.0 1.5
103. Tests and Adjustment of Sighting and Fire ControlEquipment
a. Scope of Tests. Six tests will be conductedin which-the candidate will be required to demon-strate the methods employed in making the pre-scribed tests and authorized adjustments, or de-scribe the action taken (i.e., send to the ordnancemaintenance company) if adjustment is notauthorized to be made by using personnel.
b. Special Instructions.(1) The gun will be prepared for the tests as
indicated in paragraphs 54 and 55.(2) The equipment needed for the tests is
listed in paragraph 54.(3) The candidate will select an assistant
who will operate the elevating handwheelat the direction of the candidate duringtests 1 and 2 and adjust and aline thetesting target at the direction of thecandidate prior to test 5.
172 AGO 4816C
(4) The tests will be conducted in the chrono-logical sequence indicated in c below.After completion of test 2, the gunner'squadrant used in tests 1 and 2 will beused for test 3, with the proper correc-tion, as determined in test 1, carried onthe quadrant, provided the correctiondoes not exceed 0.4 mil.
(5) Adjustments which the candidate may berequired to accomplish will fall withinthe following limits:
(a) Elevation and angle of sit: scales, notto exceed one 100-mil graduation.
(b) Elevation and angle of site micrometerscales, not to exceed ten 1-mil gradua-tions.
(c) Rotating head and telescope mountelevation indexes, none.
(d) Rotating head and telescope mountelevation micrometer indexes, not toexceed one-fourth turn.
(e) Panoramic telescope azimuth scale, notto exceed one 100-mil graduation.
(f) Panoramic telescope slipping azimuthmicrometer scale, not to exceed ten1-mil graduations.
(6) The tube will be leveled at the conclusionof test 2 and will not be disturbed there-after.
AGO 4316C 173
c. Outline of Tests.
numbernumber | Examiner commands Action of candidate
1 PERFORM END-FOR- Performs test as pre-END TEST ON GUN- scribed in para-NER'S QUADRANT. graph 62a and b.
Calls "Error (somany) mils, quad-rant serviceable(unserviceable)"
and hands quadrantto examiner for ver-ification.
2 PERFORM MICROM- Performs test as pre-ETER TEST ON GUN- scribed in para-NER'S QUADRANT. graph 62c.
Calls "Quadrant mi-crometer is (is not)in error."
8 TEST TELESCOPE Performs tests andMOUNT. makes adjustments,
if necessary, as pre-scribed in para-graph 63b.
Calls "Cross- (longi-tudinal-) level bub-ble(s) within (with-out) allowablelimit."
Caution: Do not turncross-leveling or ele-vation knobs of thetelescope mountafter this test.
4 TEST RANGE QUAD- Performs tests andRANT. makes adjustments,
if necessary, as pre-scribed in para-graph 63c.
174 AGO 4816C
Testnumber Examiner commands Action of candidate
Calls "Ready" andsteps clear.
Note. Prior to test 6, thecross- and longitudinal-leveling of the tube andthe panoramic telescopemount will be verified bythe examiner, and thetesting target will bealined by the candidatewith help of his selectedassistant as described inparagraph 63.
5 TEST ADJUSTMENT Performs tests andOF PANORAMIC makes adjustments,TELESCOPE. as prescribed in
paragraph 63d.Calls "Ready" and
steps clear.
6 TEST ADJUSTMENT Inspects elbow tele-OF ELBOW TELE- scope for adjust-SCOPE. ment and makes ad-
justments, i f r e-quired, as describedin paragraph 57m.
Calls "Ready" andsteps clear.
d. Penalties.
(1) General. The tests are not essentiallyspeed tests. The purpose of the pre-scribed time limits is to insure that thecandidate can perform the operationwithout wasted effort.
AGO 4316C 175
(2) Test 1. No credit will be allowed if-
(a) The bubble of the gunner's quadrantdoes not center when verified by theexaminer.
(b) The error (one-half the amount of theangle which was indicated when thequadrant was first reversed and thebubble centered by moving the indexarm and micrometer) is announcedincorrectly by the candidate.
(c) The candidate fails to declare thequadrant unserviceable if the error(necessary correction) is 0.4 mil ormore.
(d) The time to complete the test exceeds2 minutes.
(3) Test 2. No credit will be allowed if-(a) The procedure is not followed cor-
rectly.(b) The time to complete the test exceeds
1 minute.(4) Test 3. No credit will be allowed if-
(a) The bubble of the gunner's quadrantis not centered in either direction.
(b) The candidate does not announce cor-rectly in regard to the status of eitherthe cross-level or the longitudinal-levelbubble.
(c) The matching indexes on the rockerand actuating arm or those on the ele-vation knob and shaft are not in coin-
176 AGO 4316C
cidence when the adjustments arecomplete.
(d) The time to complete the test and ad-justments exceeds 4 minutes.
(5) Test 4. No credit will be allowed if-(a) The elevation micrometer does not
read zero when the elevation scalereads zero.
(b) The angle of site does not read 300when the cross-level and longitudinal-level bubbles are centered.
(c) The cross-level or longitudinal-levelbubble is not properly centered.
(d) The time to complete the tests andadjustments exceeds 2 minutes.
(6) Test 5. No credit will be allowed if-(a) The candidate fails to make any ad-
justment when such adjustment isindicated.
(b) The rotating head elevation microme-ter indexes are not in coincidence.
(c) The zero line of either the azimuthscale or azimuth scale micrometer isnot in coincidence with its respectiveindex.
(d) The center line of the bore, as viewedthrough the bore sights, or the line ofsight of the telescope do not fall ontheir respective sighting points on thetesting target when all scales are setat zero.
AGO 48160 1'77
(e) The time to complete the tests and ad-justments exceeds 4 minutes and 30seconds.
(7) Test 6. No credit will be allowed if-
(a) The reticle is not horizontal.
(b) The N range line is not in coincidencewith the proper sighting line of thetesting target.
(c) The time to complete the test and ad-justment exceeds 1 minute.
e. Credit.
(1) The candidate will be scored on the gen-eral merit of his work in addition to thespecific requirements above.
(2) If the tests and adjustments are per-formed correctly within the prescribedtime limit, maximum credit will be givenas follows:
Test 1_________________________ 2Test 2…________________________ 1Test 3-___________________.____ 2Test 4-____________ ___________ 2Test 5_________________________ 2Test 6_________________________ 1
Total _____________________ 10
104. Materiel
a. Scope of Tests. The candidate will be re-quired to perform three tests as outlined below.
178 AGO 4316C
b. Special Instructions.
(1) Tests 1 and 2. For tests 1 and 2, a paulinwill be spread for the convenience of thecandidate in laying out the disassembledparts. The candidate will be allowed toselect the tools and accessories necessaryfor the performance of the tests prior to-the start of the tests.
(2) Test 3.
(a) A complete set of lubrication equip-ment authorized for use of batterypersonnel will be made convenientlyavailable on a paulin.
(b) Every type of lubricant, in plainlylabeled containers, used on the gunwill be placed conveniently on thepaulin.
c. Outline of Tests.
Testnumber Examiner commands Action of candidate
1 DISASSEMBLE Performs the opera-BREECH MECHA- tion as described inNISM AND FIRING TM 9-325, layingLOCK. the parts on the
paulin.After disassembly,
identifies all partsto examiner.
2 ASSEMBLE BREECHW Performs the opera.MECHANISM AND ~ tion as described inFIRING LOCK. TM 9-325.
AGO 4816C 179
Testnumber Examiner commands Action of candidate
3 DAILY, WEEKLY, AND Selects proper lubri-MONTHLY LUBRICA- eating equipmentTION TEST. and lubricant and
shows how and withwhich ubricant eachlubrication point isserviced. (Actuallubrication is notperformed.)
d. Penalties.
(1) The tests are not essentially speed tests.The purpose of the maximum time limitsis to insure that the candidate can per-form the operations without wastedeffort.
(2) No credit will be given if the followingtime limits are exceeded:
Test 1_______________ 11/2 minutesTest 2_______________ 3 minutesTest 3_______________ 2 minutes
(3) A penalty of one-half point will be as-sessed for each component part not cor-rectly identified or omitted in test 1.There is no time limit imposed on theidentification of component parts. How-ever, the examiner may reduce the gradeif it becomes obvious that the candidateis not familiar with the nomenclature.
180 AGO 4316C
e. Credit.(1) The candidate will be scored on the gen-
eral merit of his work in addition to thespecific requirements above.
(2) If each test is performed correctly withinthe prescribed time limit, maximumcredit will be given as follows:
Test 1_________________________ 3Test 2______________________-__ 3Test 3__________--------------- 4
Total _____________________ 10
AGO 416C 181
APPENDIX
REFERENCES
AR 600-70_______ Badges.ATP 6-300 ______-Field Artillery Unit Training Program.ATT 6-1 ________.Training Tests for Field Artillery How-
itzer or Gun Battery.ATT 6-2 ________.Training Tests for Field Artillery Bat-
talion Firing.ATT 6-5_-______ . Training Tests for Light and Medium
Field Artillery Battalions, InvolvingDisplacement and Continuous FireSupport.
SR 110-1-1 ___--- Index of Army Motion Pictures, Kine-scope Recordings, and Film Strips.
SR 310-20-series_ List of Military Publications.SR 320-5-1______-Dictionary of United States Army
Terms.SR 385-310-1_ _--Regulations for Firing Ammunition for
Training, Target Practice, and Com-bat.
SR 615-25-15-----Military Occupational Specialties.SR 615-25-20 __-- Career Fields.SR 700-45-5 ___-- Unsatisfactory Equipment Report.T/O&E 6-317-____Field Artillery Battery, 105-mm How-
itzer, Self-Propelled, Armored orHowitzer Company, Armored CavalryReconnaissance Battalion.
TF 3-1407 _______Decontamination Procedures-Part I:Basic Techniques.
FM 5-15-------- .Field Fortifications.FM 5-20--______ . Camouflage, Basic Principles.FM 5-20B _______Camouflage of Vehicles.FM 5-20D _______Camouflage for Field Artillery.
182 AGO 4316C
FM 5-25_-_______.Explosives and Demolitions.FM 6-40_--______ Field Artillery Gunnery.FM 6-101________.T The Field Artillery Battalion.FM 6-125 ________Qualification Tests for Specialists, Field
Artillery.FM 6-140 ________The Field Artillery Battery.FM 17-50 ------_ Logistics, Armored Division.FM 21-5_----____ Military Training.FM 21-8_--______ Military Training Aids.FM 21-40________-Defense Against Chemical Attack.FM 21-60----____ Visual Signals.FM 23-65 -_______.Browning Machine Gun, Caliber .50 HB,
M2.FM 25-10 _______ Motor Transport.LO 9-749 _______- Carriage Motor, 105-mm Howitzer,
M7B1.TM 3-220________ Decontamination.TM 6-605--______ Field Artillery Individual and Unit
Training Standards.TM 9-324________ 105-mm Howitzer M4 (Mounted in
Combat Vehicles).TM 9-325 --_______105-mm Howitzer M2A1, Carriages
M2A1 and M2A2, and Combat VehicleMounts M4 and M4A1.
TM 9-575 _______.Auxiliary Sighting and Fire ControlEquipment.
TM 9-717_--_____ 105-mm Howitzer Motor Carriage M37.TM 9-731E _____- Carriage Motor, 105-mm Howitzer, M7.TM 9-735________-Medium Tanks M26 and M45.TM 9-749 --_____ Carriage, Motor, 105-mm Howitzer
M7B1.TM 9-850________-Abrasive, Cleaning, Preserving, Seal-
ing, Adhesive, and Related MaterialsIssued for Ordnance Materiel.
TM 9-3007_______ 105-mm Howitzers M2A1, 105-mmHowitzer Recoil Mechanisms M2A1,M2A2, and M2A3, 105-mm HowitzerCarriages M2A1 and M2A2, and 105-mm Howitzer Mounts M4 and M4A1.
AGO 4316C 183
TM 9-1527 _____. Gunner's Quadrant M1 and M1918 andMachine Gun Clinometer M1917.
TM 9-1545-______ Telescope Mounts and Range and Ele-vation Quadrants, for Motor Car-riages, Field Artillery and Antiair-craft Artillery.
TM 9-6111_______ Panoramic Telescopes M1, M12, M12A2,M12A5, and M12A6.
TM 9-1590_______ Fuze Setters M14, M22, M23, M25, andM27.
TM 9-1900 _______Ammunition, General.TM 9-1901_______.Artillery Ammunition.TM 9-2300-______ Artillery Materiel and Associated
Equipment.TM 9-2810 .._______Tactical Motor Vehicle Inspection and
Preventive Maintenance Services.TM 9-2853_______ Preparation of Ordnance Materiel for
Deep Water Fording.TM 21-301_______-Driver Selection, Training and Super-
vision, Half-Track and Full-TrackVehicles.
TM 21-305 _______Driver's Manual.TM 21-306_______-Manual for the Full-Track Vehicle
Driver.DA ORD Supply
Manuals:SNL G-199___Carriage, Motor, 105-mm Howitzer,
M7B1.SNL K-1____ Cleaning and Preserving Materials.SNL R-1 ____Ammunition for Light Artillery.SNL R-3 --__Fuzes and Primers.SNL R-7 ----- Demolition Materiel, Land Mines, and
Fuzes.DA Form 468 ____Unsatisfactory Equipment Report.00 Form 5825--__ Artillery Gun Book.
184 AGO 4316C
INDEX
Paragraphs Page
Action, to prepare for --_______________.___ 16 16Aiming:
Circle method (bore sighting) _------- 59 103Point displacement corrections --______. 43 75Point, distant ____________---------- 43 75Posts -______________-------------- 43 75
Ammunition:Assembly trough -_________________. 49 96Care of _------_-----------_------- 49 84Safety precautions -__-__-__-__-____ 84 148
Assembly trough, ammunition -___-__--- _ 49 86
Basic periodic tests:General ______________---------____ 61 111Fuse setters --- _____-_______-__-__ 64 120Ordnance check __- _________________ 65 121Test of:
Gunner's quadrant_--_--__.__ .__ 62 112Telescope mount ___--_-- ______- 63 115
Basic periodic tests, bore sighting and:Equipment ______-____---______ 54 88Purpose and scope -_--_--_--_-- ____. 53 88
Battery, in, definition of --------------_ _ 2 3Board, section data---------------------- 50 86Bore sighting:
Aiming circle method -------------- _ 59 103Conditions …__________________-_____. 56 93Distant aiming point method ---- ____ 59 102General---------------------------- 55 90Standard angle method -------------_ 60 106Testing target method _--_--__- _____ 57 94
AGO 4316C 185
Paragraphs Pace
Bore sighting and basic periodic tests:Equipment________ -. . ____________ 54 88Purpose and scope _________________. 53 88
Call off---__________________ ___________ 9 10Cannoneers, general duties of_--_________. 6 7Capabilities of motor carriage--__________ -3 4Care of ammunition ____________________- 49 84Cease firing ___________________________. 45 82Change posts_________________________ - -11 12Changes in data during firing ____________ 46 83Chief of section, duties:
Direct fire ________________________33, 38 65,72.General__________________________ - -6 7In firing __________________________. 21 20
Composition of howitzer section______-- __ 5 7Conduct of fire (direct) -_-___-- __-__---__ 32 59
Data:Board, section _____________________ 50 86Changes in, during firing--____________. 46 83
Decontamination:Biological and radiological----------- 78 144Chemical agents____________________ 77 143General-__--______ -_________-___ 76 143References _______________________ 79 145
Definitions and terms ___________________ 2 3Description of equipment______________ - -3 4Destruction of equipment:
General --__________________________ 80 146Methods__--_______________________. 81 147References--_______________________ 82 147
Direct laying, general __--_______ -______ 29 56Dismount, to --___________________ _____. 13 15Dismounted posts ______________________… 10 11Displacement corrections, aiming point___ 43 75Distant aiming point-_______-___. ________ 43 75
Method (bore sighting) - -___________ 59 102
186 AGO 4316C
Paragraphs PageDriver, duties of:
General --____________________------ 6 7In firing -__________________________ 28 55
Duties:Chief of section (direct fire)-,____ __ 33, 38 65, 72Gunner (direct fire) .________________34, 39 68, 72In firing:
Chief of section --_______ _---__-- 21 20Driver --___________________-__- 28 55General --_______________________ 20 19Gunner ._______________________ 22 30No. 1_________________________ - -23 41No. 2 --________________________ 24 45No. 3 --_________________________ 25 47No. 4 --_________________________ 26 52No. 5 - -_________________________ 27 54
In inspection:After operation_______________ - -74 134Before operation --_____________- 71 124During halt .__________________. 73 132During operation (march)_______ -- 72 131Weekly --__________________ ____ 75 139
In march order .___________________. 17 18In prepare for action________________ 16 16No. 1 (direct fire)__________________ 35, 40 70, 73No. 5 (direct fire) --_________________ 36 70Of individuals (in firing)--____________. 20 19Of personnel, general-_________-_____ 6 7Remainder of section (direct fire)_ __ 37, 41 71, 74
Equipment, description of------__--_---. 3 4
Fall:In _--______.__--__--_--_._--------- 9 10Out ------------------------------. 14 15
Field of fire___ ------------------------ 31 58Fire:
Conduct of (direct) --________________ 32 59Field of---------_-------------- --- 31 58
AGO 48160 187
Paragrapha Page
Firing, cease __________________________. 45 82Form the section, to_-___--_-- ___________ 9 10Front, definition of__________________ -. __ 2 3Fuze setters (basic periodic test)_______ 64 120
General duties of personnel______________ 6 7Gunner, duties:
Direct fire ________________________ 34, 39 68, 72General-___________________________ 6 7In firing __------------------------. 22 30
Gunner's quadrant (basic periodic test)___. 62 112Gunners, tests for qualification of:
Direct laying:Elbow telescope ____________…___ 95 159Panoramic telescope ___________… - 94 157
Displacement correction_____________ 99 167General instructions________________ -92 154Indirect laying, deflection only-______ 96 160Laying for elevation with:
Gunner's quadrant ____________- 99 165Range quadrant_______________. 97 164
Materiel ____________________--_--_. 104 178Measuring:
Deflection_____________________ 102 171Elevation _________-- ______---_. 101 170Site to the mask________________ 100 169
Outline of tests _______--------- --- 93 156Purpose and scope__________________ 91 153Tests and adjustment of sighting and 103 172
fire control equipment.
Hand signals __________________________ 51 87
In battery, definition of _________________ 2 3Individual duties in:
March order _______________________ 17 18Prepare for action _________________. 16 16
Inspection, duties in:After operation____________________ -74 134
188 AGO 4316C
Paragraphs Page
Inspection, duties in-ContinuedBefore operation --__________________ 71 124During halt_________-__------------ 73 132During operation (march)___________ - - 72 131Weekly____________________________ 75 139
Inspections, maintenance and:Disassembly, adjustment, and as- 67 122
sembly.General ______________-___________ 66, 70 122, 123Maintenance (references) ___________ 69 123Records --__________________________ 68 122
Instruction, general, duties in firing______ -- 19 19instructions, section drill________________ 8 9
Laying, precision in ____________________ 42 75Left, definition of_______________________ 2 3Limitations of motor carriage____________ 3 4
Maintenance and inspections:Disassembly, adjustment, and as- 67 122
sembly.General___________________________ 66, 70 122, 123Records _________________________-_ 68 122
Maintenance (references) _______________ 69 123March order --________________________-- 17 18Misfires (safety precautions)--__________. 85 149Mistakes _ --_________________________._ 8 9Mount, to______________________________ 12 13Mounted posts --______________---------- 10 11
No. 1, duties:Direct fire _________________________35,40 70, 73In firing --_________________________. 23 41
No. 2, duties in firing__________________ - -24 45No. 3, duties in firing--_________-________- 25 47No. 4, duties in firing________________ _ - - .26 52No. 5, duties:
Direct fire ________________________- 36 70In firing --_________________________. 27 54
AGO 4316C 189
Paragraphs Page
Objective (of section drill) __-- __________ 7 9
Performance characteristics, motor car- 3 4riage.
Posts:Aiming …____________________…- - -- _ 43 75Of the section _____________________. 10 11To change _______________-_________ 11 12
Precision in laying _______-____-_________ 42 75Preparation of range card------____-____. 30 57Preparations for firing, general --__________ 15 16Prepare for action _______________--__--. 16 16Prepared for action, posts------_________- 10 11Purpose and scope_-_____-----__--------- 1 3
Qualification of gunners, tests for:Direct laying:
Elbow telescope __----___-______ 95 159Panoramic telescope ____________ 94 157
Displacement correction_____________ 99 167General instructions -_______________ 92 154Indirect laying, deflection only _--___ 96 160Laying for elevation with:
Gunner's quadrant_----_________ 98 165Range quadrant _________-_____. 97 164
Materiel __________________________. 104 178Measuring:
Deflection_---______-- __________ 102 171Elevation --- __________________ - 101 170Site to the mask _----__________ 100 169
Outline of tests--_____---- __________ 93 156Purpose and scope _________________. 91 153Tests and adjustment of sighting and 103 172
fire control equipment.
Range card, preparation of-_________-____ 30 57Reference lines, vertical ______________-_ 44 79References __________________________ 4, App. 5, 182
190 AGO 4816C
Paragraphs Page
Remainder of section, duties (direct fire)__ 37, 41, 71, 74,65 121
Resume firing in another position_________ 18 18Right, definition of _____________________ 2 3Rotation of duties ____________________-_ 8 9
Safety precautions:Ammunition _______-_____________-- 84 1f8Drill and firing --___________________. 86 150General --__________________________ 83 148Misfires -----_-------___ ___________ 85 149
Scope, purpose and ---------------- _____ 1 3Section:
Composition of __________________--. 5 7Data board---__--_--_-_____--______ 50 86Definition of ______________________- 2 3Drill, objective _____________________ 7 9
Signals:Hand -------------------------- __-- 51 87Touch -____________---------------. 52 87
Standard angle method (bore sighting)___ 60 106
Table I. Duties in preparing for action____ 16 16Table II. Duties in preparing for traveling_ 17 18Target, testing --- ______________--_____ 44 79Telescope mount (basic periodic test)_____ 63 115Terms,'definitions and------------------- 2 3Test of:
Gunner's quadrant (basic periodic 62 112test).
Telescope mount (basic periodic test)_. 63 115Testing target _________---------------- 44 79
Method (bore sighting) --____________ 57 94Tests for qualification of gunners:
Direct laying:Elbow telescope ----___________. 95 159Panoramic telescope -___________ 94 157
Displacement correction ____________. 99 167General instructions----_____________ 92 154
AGO 4816C 191
Paragraphs PageTests for qualification of gunners-Con-
tinuedIndirect laying, deflection only-______ 96 160Laying for elevation with:
Gunner's quadrant______________ 98 165Range quadrant _______________. 97 164
Materiel __________________________. 104 178Measuring:
Deflection ---- _______---____-- _ 102 171Elevation _----_______________- 101 170Site to the mask _______________ 100 169
Outline of tests ----_______ _________ 93 156Purpose and scope _________.________. 91 153Tests and adjustment of sighting and 103 172
fire control equipment.To form the section --- _________________ 9 10Touch signals _______-- _____-__________. 52 87Training:
Conduct of _____________--___------ 89 151Objectives _____________-------__--. 88 151Purpose and scope ______-- -- ___----. 87 151Standards to be attained_--________-_ 90 152
Trough, ammunition assembly -__________ 49 86
Unload the gun, to ._-----___------. __---- 47 o 83Unloading ____________--__----__---_--- 47 83
Vertical reference lines __-- __------ __--- . 44 79
192 AGO 4316C
[AG 472.2 (23 Dec 56)]
BY ORDER OF THE SECRETARY OF THE ARMY:
M. B. RIDGWAY,General, United States Army,
OFFICIAL: Chief of Staff.WM. E. BERGIN,
Major General, United States Army,The Adjutant General.
DISTRIBUTION:
Active Army:GSUSA (5); Tech Svc (1); Tech Svc Bd (1);AFF (10); AA Comd (2); OS Maj Comd (5);Base Comd (5); MDW (2); Log Comd (2); A(3); CHQ (2); Div 17 (5); Brig 6 (2); Regt6 (2); FT (2); USMA (5); Sch (2) except 6(500), 17 (25); PRGR 9 (2); RTC 6 (100), 17(25); PMS&T 6 (1); Mil Dist (3); T/O & E,6-315(10); 6-317(25).
NG: Same as Active Army except 2 copies to eachunit.
USAR: Same as Active Army except 2 copies to eachunit.
For explanation of distribution formula, see SR 310-90-1.
' U. S. GOVERNMENT PRINTING OFFICE: 1954-270641
AGO 4816C19'3