sensitivity analysis of the 408 cheytac with 419 heavy bullet

Ballistics Analysis of the 408 CheyTac Cartridge 419 gr. Heavy Bullet Configuration

This study confirms the preliminary ballistics report written to determine the potential capabilities of the .408 CheyTac cartridge in conjunction with the THOR M408 rifle as the chosen delivery system. This analysis contains information on the Danger Space dimensions of the .408 CheyTac cartridge. Many external ballistics analysis contain information such as remaining velocity, remaining energy (ft. lbs.), bullet drop, etc. Much of this information is useless to the tactical sniper as it is generally considered that if you can hit the target under unknown distance conditions, you will put that target down. Energy is irrelevant with a 419 gr. bullet at 2000 meters if you can simply strike that target. What counts for the tactical sniper when considering a weapon of suggested higher performance than his current weapon?

How accurate do I have to be in my range determinations?

How much better does this new system resist deflection caused by wind?

How resistant is this new bullet in flight to changes in air temperature, barometric pressure, etc.?

The Danger Space dimension tells the sniper how much error his can make in his range determination and still strike the target within allowable parameters, usually considered to be 2 minutes of angle. With that said, it is acceptable to state that the size of a target at ANY range is only two minutes of angle, or the

Ballistics Analysis of the 408 CheyTac Cartridge 419 gr. Heavy Bullet Configuration A supplementary document for the THOR Global Defense Group M408 Weapon System

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size in inches representing that 2 Minute of Angle figure. When considering a new rifle/ammunition it is quite reasonable to consider the most important pieces of data as Danger Space and Resistance to Windage Deflection. All other pieces of information would serve to support the above data. Data for comparison is used for comparison against selected high performance cartridges and bullets in use with current military cartridges. The cartridges and data used are as follows:

M118 / M118 (LR) Special Ball – Current issue for the M-24 SWS, USMC M40A1 and Naval Special Operations SWS. A-191, .300 Winchester Magnum: The current cartridge for the very limited service, M-91 .300 Winchester Magnum. This rifle is very limited in issue. It is available in Naval Special Warfare units and available to US Army SOF units through the Joint Operational Stocks facility. .338 Lapua (for comparison only): Not currently in use within the US military or SOF units. Configured with the .300 gr. Sierra Matchking at a velocity of 2850 fps. .50 BMG, Mark 211, MOD-0 (Raufoss): Current military cartridge of choice for the .50 caliber SWS. In use by all branches of service.

.50 BMG, 750 Gr. Horn day AMAX (for comparison only): This configuration is being considered for limited special issue to US and Allied Forces. .408 CheyTac, 419 Gr. Solid bullet: The data used to determine the ballistic characteristics of the .408 are finalized. The ballistic performance of the 419 gr. bullet predicted in the previous report is confirmed in this report. The base ballistic co-efficient of the 419 gr. bullet is .903 when launched at a velocity of 2890 fps.

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EXECUTIVE SUMMARY: This summary gives the key gains of the .408 CheyTac cartridge over the three primary military sniping cartridges used by US Armed Forces at this time. This includes both the conventional and Special Operations Forces available weapons and cartridges. The cartridges listed that are NOT part of the US inventory will not be covered in this summary. Performance data is listed in order or precedence for the ranges listed.


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DANGER SPACE DATA1: Data is presented for a desired kill zone on the target of 2 Minutes

of Angle in size at the given range. See tables for actual Danger Space dimensions additional data.

At 1000 meters, the 408 is 179% more efficient than the M-24SWS / M118, 36% more efficient than the .300 Winchester Magnum and 51% more efficient than the .50 Caliber SWS / Raufoss. At 1500 meters, the 408 is 61% more efficient than the .300 Winchester Magnum / A-191 and 85% more efficient than the .50 Caliber SWS / Raufoss. At 2000 meters, the 408 is 85% more efficient than the .50 Caliber SWS / Raufoss.

WINDAGE DEFLECTION (given in inches for a 10 mph crosswind) DATA: At 1000 meters, the 408 is 178% more efficient than the M-24SWS / M118, 66% more efficient than the .300 Winchester Magnum and 66% more efficient than the .50 Caliber SWS / Raufoss. At 1500 meters, the 408 is 76% more efficient than the .300 Winchester Magnum / A-191 and 74% more efficient than the .50 Caliber SWS / Raufoss. At 2000 meters, the 408 is 68% more efficient than the .50 Caliber SWS / Raufoss.

ELEVATION REQUIREMENTS (Minutes of Angle) DATA At 1000 meters, the 408 is 95% more efficient than the M-24SWS / M118, 12% more efficient than the .300 Winchester Magnum and 26% more efficient than the .50 Caliber SWS / Raufoss. At 1500 meters, the 408 is 29% more efficient than the .300 Winchester Magnum / A-191 and 50% more efficient than the .50 Caliber SWS / Raufoss. At 2000 meters, the 408 is 57% more efficient than the .50 Caliber SWS / Raufoss.

1 Danger space is a horizontal dimension that is used for several things. In its basic terms in sniping it tells us how much error we can have in the range determination for a given range and given shooting scenario. Additional information at the end of this analysis. (Page 12).


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408 CheyTac Sensitivity to Changes in Air Temperature. The .408 CheyTac is 92.9% at 1000 Meters to changes in the air temperature, 125.6% at 1500 Meters, and 130.1% at 2000 Meters more efficient, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.

408 CheyTac Sensitivity to Changes in Barometric Pressure. The .408 CheyTac is 106.3% at 1000 Meters to changes in the barometric pressure, 128% at 1500 Meters, and 109.2% at 2000 Meters more efficient, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.

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General: In military sniping, the main critical factor that snipers must determine is the range to the target. Failure to do this with required accuracy makes all other data, calculations and corrections moot. Snipers that are going to engage targets in the 1500 meter + spectrum must determine the range to the target with extreme levels of precision. There are no instruments in use at this time that allow the type of precision needed to engage 2 Minute of Angle targets to ranges of 1500+ meters. The major factors in determining the range depends on several factors. These include:

The ability of the sniper team to see the target.

The quality of the optics used to determine the range to the target.

The method of range finding itself.

The willingness of the target to stand still long enough for most taught rangefinding methods to be used.

The skill of the sniper team in rangefinding.

There are three points of data that are used to compare the above mentioned cartridges against each other to show the gain of one cartridge over the other at the ranges indicated.

These data are:

Danger Space Dimensions (Table 1a, b, c).


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In military sniping we use the figure known as “Danger Space” (DS) as a ruler to use when determining the range to the target. In determining the danger space for a given cartridge, scenario and range we need three pieces of information:

1. Height of the target. Clearly the overall height of the target is NOT

what the sniper is trying to hit. For the purposes of this document, several allowable strike zone measurements are used. These are presented in Minutes of Angle and inch dimensions in the table data. (1a, b, c) Normally the total height of the target is used in this data. For sniping we have to use the height of the critical killing zone on a target. While the height of a 6’ man will yield a workable Danger Space figure, we have to hit a much smaller target that 6’. We use the standard of 2 Minutes of Angle. So at 1000 yards the height of the target becomes 20”.

2. Fall Angle. We must know the fall angle of the bullet as it passes

through a vertical plane at the range at which we are shooting. For the 7.62mm NATO at 1000 yards this angle is 1.4197 degrees. The steeper the angle of fall of the bullet, the shorter the Danger Space dimension will be. This means that any range determination must be that more precise. Shallow fall angles result in more allowable range determination error.

3. Range in Yards or Meters. This is needed a part of the DS formula.

In addition to these three elements, it is in some circumstances required to have a measure of the Height of the barrel off of the ground. In low angle trajectories (under 10 degrees) and in ranges past 600 meters, this factor is small and is ignored. When considering an intended range of 1200 meters, the ability of handling unknown distance problems is paramount. The data in this study is used to show the effectiveness of three cartridges in overcoming some of the shortfalls in performance and training for military snipers. Range finding is difficult and at times impossible. Rangefinding at night is nearly impossible with current issued systems.

Elevation Requirements (Table 2): This data is a comparison of the elevation requirements of the cartridges that are listed. Essentially, whichever cartridge needs the least amount of elevation at any given range is more efficient (for elevation) than other cartridges listed. The data is presented in increasing efficiency from left to right. Each cartridge is listed in ascending order. A percentage of gain is presented to show the level of efficiency of one cartridge over the one previous. The .408 CheyTac is the last listed cartridge along with a percentage comparison against all other cartridges.


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Windage Deflection Data (Table 3): This data is a comparison of the windage deflection of the listed cartridges by a 10 mph wind at the ranges indicated. The next most difficult factor (after range determination) of combat sniping is that of wind determination and correction (author’s opinion). Each cartridge is listed in ascending order. A percentage of gain is presented to show the level of efficiency of one cartridge over the one previous. The .408 CheyTac is the last listed cartridge along with a percentage comparison against all other cartridges. Additional Data (Tables 4 and 5): This data is a comparison of the listed cartridges sensitivity to changes in air temperature and air pressure. The air temperature data (table 4) reflects the effects on the bullet in flight over a

temperature range of 30 to 110 F. The air pressure data (table 5) reflects the effects on the bullet in flight over a Barometric Pressure range of 26.53 In. Hg. – 31.53 In. Hg.


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GROUP SHOT AT 2000 YARDS 15” Extreme Spread

419 GR. PROJECTILE

83.50 MOA ELEVATION


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1. Columns that are darkly shaded represent the current military cartridges in use for combat sniping.

2. Columns that are lighter shaded are comparison data for the .408 CheyTac vs. all other cartridges.

Table 1a: DANGER SPACE DATA /// 1000 METER SHOT The term “height of target” is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.

Height of Target /

Acceptable Group Size

7.62 M118

300 WM A-191

% GAIN vs. 762

50 BMG Raufoss

% GAIN vs.

300 WM

338 Lapua

% GAIN vs.

Raufoss

50 BMG AMAX

% GAIN vs.

338 Lap

408 CheyTac

% GAIN vs. 762

% GAIN vs.

300 WM

% GAIN vs.

Raufoss

% GAIN vs.

338 Lap

% GAIN vs.

AMAX

72” 6.3 MOA

72m 120m +67% 112m +8% 138m +4% 152m +13% 214m +189% +73% +60% +54% +37%

56.9” 5.0 MOA

56m 93m +66% 87m +9% 107m +3% 118m +13% 164m +186% +72% +58% +54% +36%

45.5” 4.0 MOA

44m 73m +66% 69m +8% 84m +4% 92m +12% 128m +182% +70% +57% +51% +35%

34.1” 3.0 MOA

33m 54m +64% 51m +7% 62m +5% 68m +11% 94m +176% +69% +57% +49% +34%

22.8” 2.0 MOA

21m 35m +67% 33m +11% 40m +3% 45m +13% 61m +181% +69% +51% +48% +34%

11.4” 1.0 MOA

10.6m 18m +70% 30m +6% 20m +5% 22m +10% 30m +174% +61% +53% +45% +34%

Table 1b: DANGER SPACE DATA /// 1500 METER SHOT The term “height of target” is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.

Height of Target /


300 WM A-191

50 BMG Raufoss

% GAIN vs.

300 WM

338 Lapua

% GAIN vs.

Raufoss

50 BMG AMAX

% GAIN vs.

338 Lap

408 CheyTac

% GAIN vs.

300 WM

% GAIN vs.

Raufoss

% GAIN vs.

338 Lap

% GAIN vs.

AMAX

72” 4.2 MOA

43m 45m +5% 48m +7% 66m +38% 89m +107% +98% +85% +35%

56.9” 3.0 MOA

34m 35m +3% 38m +9% 52m +37% 70m +106% +100% +84% +35%

45.5” 2.0 MOA

27m 28m +4% 30m +7% 41m +37% 55m +104% +96% +83% +34%

34.1” 1.0 MOA

20m 21m +5% 23m +10% 31m +35% 41m +105% +95% +78% +32%


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Table 1c: DANGER SPACE DATA /// 2000 METER SHOT The term “height of target” is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.

Height of Target /


50 BMG Raufoss

50 BMG AMAX

% GAIN vs.

Raufoss

408 CheyTac

% GAIN vs.

Raufoss

% GAIN vs.

AMAX

72” 4.2 MOA

17m 20m +18% 25m +47% +25%

56.9” 3.0 MOA

14m 16m +14% 20m +43% +25%

45.5” 2.0 MOA

11m 13m +18% 16m +45% +23%

34.1” 1.0 MOA

8m 9.6m +20% 12m +50% +25%

The figures presented in METERS in tables 1a, b, and c represent an allowable error in range determination.

It is interesting to note that using current state of the art military laser range finders associated with sniping operations CANNOT accurately report ranges to the target within the danger space dimensions of current sniping cartridges.

For example, using the .50 Caliber SWS and Raufoss ammunition; a 1500 meter shot requiring 2 MOA of precision dictates that a range determination within 20 meters be obtained. This is 1.3% of the true range. By splitting that 11 meter figure in half (6.5 meters), you also have the same printed error that occurs with the Melios LRF under the best conditions.

For example, using the .408 CheyTac to shoot a 3 MOA allowable shot group size on a target at 1500 meters means that the sniper team’s range determination calculations must be between 1490 and 1510 meters. Any calculated ranges outside of that parameter means the shots will be short (or low on the target) or long (or high on the target).


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Table 2: ELEVATION REQUIREMENTS (Minutes of Angle) PERFORMANCE ANALYSIS

RANGE Meters

7.62 M118

300 WM A-191

% GAIN vs. 762

50 BMG Raufoss

% GAIN vs.

300 WM

338 Lapua

% GAIN vs.

Raufoss

50 BMG AMAX

% GAIN vs.

338 Lap

408 CheyTac

% GAIN vs. 762

% GAIN vs.

300 WM

% GAIN vs.

Raufoss

% GAIN vs.

338 Lap

% GAIN vs.

AMAX

100M 2.8 2.1 +33% 2.4 +9% 2.50 No Gain 2.50 No Gain 2.25 +22% +11% No Gain +11% +11% 200M 5.9 4.4 +34% 4.9 +10% 4.75 No Gain 5.25 -9% 4.50 +33% +17% +6% +5% +16% 300M 9.4 7.0 +34% 7.6 No Gain 7.50 No Gain 8.00 -6% 7.50 +27% No Gain No Gain No Gain +6% 400M 13.3 9.7 +37% 10.6 -5% 10.50 No Gain 11.25 -6% 10.00 +36% No Gain +5% +5% +13% 500M 17.7 12.9 +37% 13.9 -7% 13.50 +2% 14.50 -6% 12.75 +43% No Gain +8% +6% +14% 600M 22.8 16.3 +40% 17.4 -9% 17.00 +3% 18.00 -5% 15.50 +52% +3% +13% +10% +16% 700M 28.6 20.2 +42% 21.2 -8% 20.50 +4% 21.50 -5% 18.75 +59% +4% +13% +10% +15% 800M 35.3 24.5 +44% 25.5 -8% 24.50 +4% 25.50 -4% 22.00 +70% +7% +16% +11% +16% 900M 43.3 29.4 +47% 30.2 -8% 29.00 +5% 29.75 -3% 25.50 +82% +10% +20% +14% +17% 1000M 52.7 34.9 +51% 35.3 -11% 33.50 +9% 34.25 -2% 29.25 +95% +12% +26% +15% +17% 1100M 41.4 40.9 -11% 38.75 +10% 39.00 -0.5% 33.25 +15% +29% +17% +17% 1200M 48.8 47.2 -10% 44.25 +11% 44.50 -0.5% 37.50 +19% +31% +18% +19% 1300M 57.4 54.2 -11% 50.50 +14% 50.00 +1.0% 42.00 +22% +37% +20% +19% 1400M 65.2 62.1 -13% 57.25 +18% 56.25 +2% 47.00 +26% +44% +22% +20% 1500M 73.3 74.6 -14% 64.25 +22% 63.00 +2% 52.25 +29% +50% +23% +21% 1600M 79.6 72.50 +23% 70.25 +3% 58.00 +54% +25% +21% 1700M 87.9 81.25 +23% 78.00 +4% 64.00 +57% +27% +22% 1800M 96.7 90.50 +22% 86.50 +5% 70.50 +57% +28% +23% 1900M 105.9 100.75 +21% 95.75 +5% 77.50 +57% +30% +24% 2000M 1 111.50 +20% 105.75 +5% 85.25 +57% +31% +24% 2100M 146.25 116.50 93.25 +57% +25% 2200M 159.25 127.50 102.00 +56% +25% 2300M 172.25 139.75 111.25 +55% +25% 2400M 186.00 152.50 121.00 +54% +26% 2500M 200.75 166.25 131.50 +53%

Table 3: WINDAGE DEFLECTIONS ANALYSIS – (inches) 10 MPH Speed


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RANGE Meters

7.62 M118

300 WM A-191

% GAIN vs. 762

50 BMG Raufoss

% GAIN vs.

300 WM

338 Lapua

% GAIN vs.

Raufoss

50 BMG AMAX

% GAIN vs.

338 Lap

408 CheyTac

% GAIN vs. 762

% GAIN vs.

300 WM

% GAIN vs.

Raufoss

% GAIN vs.

338 Lap

% GAIN vs.

AMAX

100M 1.0” 0.6” +66% 0.6” No Gain 0.5” +20% 0.5” No Gain 0.4” +150% +50% +50% +25% +25% 200M 3.8 2.4 +58% 2.5 No Gain 2.3 +4% 1.8 +28% 1.6 +137% +50% +50% +44% +13% 300M 9.0 5.6 +60% 5.7 -2% 5.2 +10% 4.2 +24% 3.8 +137% +47% +50% +37% +11% 400M 16.6 10.3 +61% 10.4 -1% 9.5 +10% 7.7 +23% 6.8 +144% +51% +53% +40% +13% 500M 27.1 16.7 +62% 16.8 -0.5% 15.3 +10% 12.4 +23% 10.9 +149% +53% +54% +40% +14% 600M 40.9 24.8 +65% 25.0 -0.8% 22.6 +11% 18.3 +23% 16.0 +156% +55% +56% +41% +14% 700M 58.3 35.1 +66% 35.3 -0.5% 31.6 +12% 25.6 +23% 27.3 +161% +57% +58% +42% +15% 800M 79.7 47.6 +67% 47.9 -0.6% 42.4 +13% 34.4 +23% 29.8 +167% +60% +61% +42% +15% 900M 105.3 62.7 +68% 62.9 -0.3% 55.0 +14% 44.8 +23% 38.5 +174% +63% +63% +43% +16%

1000M 134.9 80.5 +68% 80.6 -0.1% 69.7 +16% 56.9 +22% 48.6 +178% +66% +66% +43% +17% 1100M 101.4 101.2 +0.2% 86.6 +17% 70.9 +22% 60.2 +68% +68% +44% +18% 1200M 125.7 124.9 +0.5% 105.8 +18% 86.9 +22% 73.4 +71% +70% +44% +18% 1300M 143.1 151.6 +1% 127.4 +19% 105.1 +21% 88.2 +74% +72% +44% +19% 1400M 183.8 181.4 +1% 151.5 +20% 125.5 +21% 104.8 +76% +73% +45% +20% 1500M 217.4 214.1 +2% 178.0 +20% 148.3 +20% 123.2 +76% +74% +44% +20% 1600M 249.3 207.1 +20% 173.6 +19% 143.6 +74% +44% +21% 1700M 286.9 238.4 +20% 201.3 +18% 166.0 +73% +44% +21% 1800M 326.7 272.0 +20% 231.3 +17% 190.4 +72% +43% +21% 1900M 368.6 307.6 +20% 273.5 +17% 216.9 +70% +42% +21% 2000M 412.6 345.1 +19% 297.8 +16% 245.5 +68% +41% +21% 2100M 458.4 334.1 276.1 +66% +21% 2200M 506.1 372.2 308.5 +64% +21% 2300M 555.6 412.1 342.7 +62% +20% 2400M 606.9 453.6 378.5 +60% +20% 2500M 660.0 496.9 416.0 +59% +19%


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Data in BOLD are the current standard military cartridges and the .408 CheyTac for comparison.

Table 4: SENSITIVITY ANALYSIS: Changes in Air Temperature: 30-110 F.

This table compares the sensitivity of analyzed cartridges to the changes in air temperature. The data represents the total change in Minutes of Angle of an 80 Deg. F. temperature spectrum.

500 Meter Sensitivity: 30 - 110 F (Total accumulation of MOA Changes) M118 Special Ball .90 MOA A-191, 300 Winchester Magnum .50 MOA .50 BMG: Mark 211, MOD-0 .50 MOA .338 Lapua .40 MOA .50 BMG, 750 gr. AMAX .30 MOA .408 CheyTac .30 MOA

1000 Meter Sensitivity: 30 - 110 F (Total accumulation of MOA Changes) M118 Special Ball 6.30 MOA A-191, 300 Winchester Magnum 2.70 MOA .50 BMG: Mark 211, MOD-0 2.70 MOA .338 Lapua 2.30 MOA .50 BMG, 750 gr. AMAX 1.70 MOA .408 CheyTac 1.40 MOA

1500 Meter Sensitivity: 30 - 110 F (Total accumulation of MOA Changes) A-191, 300 Winchester Magnum 9.80 MOA 1.09 MOA per 10 Deg Change .50 BMG: Mark 211, MOD-0 9.70 MOA 1.08 MOA per 10 Deg Change .338 Lapua 7.60 MOA .84 MOA per 10 Deg Change .50 BMG, 750 gr. AMAX 5.30 MOA .59 MOA per 10 Deg Change .408 CheyTac 4.30 MOA .48 MOA per 10 Deg Change

2000 Meter Sensitivity: 30 - 110 F (Total accumulation of MOA Changes) .50 BMG: Mark 211, MOD-0 23.70 MOA 2.63 MOA per 10 Deg Change .50 BMG, 750 gr. AMAX 13.60 MOA 1.51 MOA per 10 Deg Change .408 CheyTac 10.30 MOA 1.14 MOA per 10 Deg Change The .408 CheyTac is 92.9% at 1000 Meters to changes in the air temperature, 125.6% at 1500 Meters, and 130.1% at 2000 Meters, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.

Table 5: SENSITIVITY ANALYSIS: Changes in Barometric Pressure: 26.53 In. Hg. – 31.53 In. Hg.


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Data in BOLD are the current standard military cartridges and the .408 CheyTac for comparison.

This table compares the sensitivity of analyzed cartridges to the changes in barometric pressure. The data represents the total change in Minutes of Angle of a total change of 05.00 In. Hg. of air pressure. 500 Meter Sensitivity: 26.53 In. Hg. – 31.53 In. Hg. (Total of MOA Changes) M118 Special Ball 1.10 MOA A-191, 300 Winchester Magnum .50 MOA .50 BMG: Mark 211, MOD-0 .50 MOA .338 Lapua .50 MOA .50 BMG, 750 gr. AMAX .40 MOA .408 CheyTac .30 MOA 1000 Meter Sensitivity: 26.53 In. Hg. – 31.53 In. Hg. (Total of MOA Changes) M118 Special Ball 11.10 MOA A-191, 300 Winchester Magnum 3.20 MOA .50 BMG: Mark 211, MOD-0 3.30 MOA .338 Lapua 2.60 MOA .50 BMG, 750 gr. AMAX 2.20 MOA .408 CheyTac 1.60 MOA 1500 Meter Sensitivity: 26.53 In. Hg. – 31.53 In. Hg. (Total of MOA Changes) A-191, 300 Winchester Magnum 11.50 MOA 1.92 MOA per 01.00 In. Hg. Change .50 BMG: Mark 211, MOD-0 11.40 MOA 1.90 MOA per 01.00 In. Hg. Change .338 Lapua 8.40 MOA 1.40 MOA per 01.00 In. Hg. Change .50 BMG, 750 gr. AMAX 6.90 MOA 1.15 MOA per 01.00 In. Hg. Change .408 CheyTac 5.00 MOA .83 MOA per 01.00 In. Hg. Change 2000 Meter Sensitivity: 26.53 In. Hg. – 31.53 In. Hg. (Total of MOA Changes) .50 BMG: Mark 211, MOD-0 24.90 MOA 4.15 MOA per 01.00 In. Hg. Change .50 BMG, 750 gr. AMAX 16.60 MOA 2.77 MOA per 01.00 In. Hg. Change .408 CheyTac 11.90 MOA 1.98 MOA per 01.00 In. Hg. Change The .408 CheyTac is 106.3% at 1000 Meters to changes in the barometric pressure, 128% at 1500 Meters, and 109.2% at 2000 Meters, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.


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MORE ON “DANGER SPACE”, “DANGER RANGE” and “SWEPT SPACE”

There is a distance in front of the muzzle in which the bullet does not riser higher than the object being fired at (or the critical component of any target). This distance is one part of Danger Space. The other part of Danger Space occurs after the bullet has passed the Maximum Ordinate (in the falling branch of the trajectory) and is again below the height of the object being fired at and continues to the ground. That part of Danger Space that occurs within the falling branch is the horizontal dimension that is part of the firing tables that we use to determine our Range Determination accuracy requirement.

Let’s take a look at the ordinate table for a 2500-meter and 1400 meter

shot. Note the height of the ordinate at 100 meters (18.9’) and for the range of 2400 meters (38.2’). There is quite a difference of the height of the bullet for these two ranges. The bullet is 49% higher at 100 meters from impact than it is 100 meters from the end of the gun. This is another indicator of the shape of the trajectory. It also indicates the steepness of the angle that the bullet is falling the final 100 meters to impact.

2500 METER ORDINATE TABLE (in feet) FOR MARK 211, MOD-0

Range 100 200 300 400 500 600 700 800 900 1000 1100 1200

ORD. 18.9 37.4 55.4 72.7 89.3 105.3 120.3 134.3 147.1 158.5 168.3 176.3

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500

182.2 185.7 186.6 184.7 179.8 171.4 159.4 143.7 123.9 99.9 85.3 38.2 0.0

1400 METER ORDINATE TABLE (in feet) FOR MARK 211, MOD-0

Range 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

ORD 6.2 11.9 17.1 21.6 25.1 28.2 30.1 30.9 30.4 28.3 24.5 18.7 10.7 0.0

At this point, it’s time to review both the definition of Danger Space and the

factors that affect the Danger Space dimension. “Danger space is a horizontal measurement expressed in yards or meters. As the bullet goes past maximum ordinate and travels downward towards impact with the ground (ignoring the target), the danger space measurement begins at the point where the bullet is equal to the top (height) of the target and continues to when the bullet impacts the ground (again, ignoring the target).”

Height of the barrel off the ground. (In these tables in this book, the barrel height is set at 6” off the ground. This matters in ranges only to about 700 yards. At the ranges used in HTI operations, this factor is irrelevant.


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Height of the target. This figure is used two ways. There is the overall height of the target. With missile targets this figure is okay, because a missile cannot sustain a hit anywhere on it without sustaining some kind of damage. On targets where there must be a specific point of attack, the size of this particular object becomes the height of the target. Whereas a 6’ (1.83 meter) tall man would appear to have a danger space dimension of 137 meters at a 1000 meter shot with .50 caliber, Mark 211, Mod-0 ammunition, the 137 meter figure

isn’t accurate.

The above figures show the depiction of a 40-meter Danger Space that was

extracted from the Danger Space table for Mark 211, Mod-0 ammunition for a 1600-meter shot. Below is the graphical depiction of the 1600 meter data.

The Danger Space dimension begins when the bullet is the same height of

the target or the critical kill zone and continues to the ground. Usually center of mass is accepted as the point of aim for the target or the critical component for attack. In the above table there is also a section referred to as the Danger Range for a shot. The Danger Range as mentioned in Chapter 4 refers to a situation where the trajectory is such that the bullet NEVER rises above the height of the target. This dimension is critical later when we discuss Reverse Image Zero and

DANGER SPACE OF SELECTED TARGET SIZES (METERS) MK-211, MOD-0

RANGE 1M 2M 3M 4M 5M 6M 7M 8M 9M 10M 11M 12M 13M 14M 15M

500M 500

600M 600 DANGER SPACE IN THIS ZONE IS REPRESENTED BY

700M 209 700 THE RANGE TO THE TARGET. MAXIMUM ORDINATE

800M 159 234 800 DOES NOT EXCEED THE HEIGHT OF THE TARGET.

900M 120 175 900 THIS IS REFERRED TO AS THE DANGER RANGE.

1000M 96 137 219 1000

1100M 76 108 168 233 1100

1200M 68 96 149 206 1200

1300M 50 70 108 147 188 231 275 1300

1400M 41 58 88 120 152 186 221 257 294 1400

1500M 34 48 73 98 125 152 180 208 237 267 298 1500

1600M 29 40 61 83 105 127 150 174 197 222 247 272 298 324 1600

GUN POSITION

DANGER SPACE DIMENSION

Example: 2 meter high target = 40 meter danger range

1600 Meter Shot / .50 caliber Mark 211, Mod-0

Target at near range

where the bullet begins the Danger

Space dimension

entry.

Target at far range where

the bullet ends the Danger Space dimension and strikes

the ground


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LINE OF SIGHT

SWEPT SPACE INCREASE

ON DOWN HILL SLOPE

Point Blank Zero shooting methods. The below depiction shows the effect of Danger Range and its trajectory curve.

The term “swept space refers to a horizontal measure that does change with the lay of the terrain. This dimension does not affect the degree of accuracy required to determine the range to the target. It doesn’t much matter whether the target is uphill or downhill as far as the degree of accuracy required when finding the range. Remember though, that uphill or downhill angle will make the target appear smaller to your and your optical systems. The only rangefinding equipment NOT affected by uphill or downhill angle is the laser range finder.

ON GROUND THAT IS RISING IN FRONT OF THE SHOOTER, THE

SWEPT SPACE DIMENSION WILL DECREASE.

ON GROUND THAT IS FALLING AWAY FROM THE SHOOTER OR SLOPING DOWNHILL, THE SWEPT SPACE DIMENSION INCREASES AND MAY EASILY CONTINUE FOR HUNDREDS OF METERS.

Consider the two rules above. In this depiction, the dotted line represents the trajectory for the point of aim on that target. The two dark lines represent the trajectories for points of aim at the top and at the bottom of the target. The swept space is the measurement on the ground that the group of shots would cover. The major effect and concern of this upwards slanting ground is that the target with only a step or two be out of the

GUN POSITION

DANGER RANGE DIMENSION = 1600 meters

Example: 2 meter high target = 40 meter danger range

1600 Meter Shot

NOTE: Trajectory does not exceed target height all the way to target.

700 METER

SHOT

DANGER RANGE = 700 meters


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cone of fire. He can easily during the time the shot is fired move uphill or downhill and the round will either pass over his head or under his feet.

In this depiction of a shot on a target that is standing on downward sloping

ground, you can see that a target would have to move quite a distance before he would be out of the cone of fire. This is a great aid to unknown distance shooters and can be used to your advantage. This rule does not apply when the shooter is located on higher ground looking down on a target that is standing on flat ground. The danger space figure is shorter because of the angel caused by the gun being higher than the target. Your range determination must be more precise. So when considering when shooting on a target and you have some choice in the terrain

around the target, the old rule of dominating the high ground is good. Try to set up so that the target is on a downhill slope from you or so that you are on higher ground. Remember the rules of swept space are written with the gun being

at the same altitude as the target. That is, there is no slant angle involved here, only that the target is standing on ground that is sloping upward or sloping downward.

Text source authored by D. Michaelis – Document Revised 2013

UPHILL SLANT

SWEPT SPACE

DECREASESLINE OF SIGHT

sensitivity analysis of the 408 cheytac with 419 heavy bullet

Documents

m118 special

darkly shaded

heavy bullet

danger space

danger space

current military

danger space

swept space