LongRangeLoadDevelopmentforthePrac5calPrecisionRifle

Part2

ByJimSee

Welcomeback!Withbrassprepara2onsoutofthewayasdetailedinpart1,wearereadytomoveontotheprocessof;powderselec2on,chargeweight,bulletselec2onandsea2ngdepth.

Themostimportanttoolintheprocessofdevelopingaloadforyourrifleisknowledge,thatknowledgeisonlyasreliableasitssource.Becauseweareworkingwithaninstrumentthatcancausegreatbodilyharmanddeath,youoweittoyourselfandtheothersaroundyoutohaveaknowledgeableworkingbasetoselectandperformaprac2ceofloadingthatissafeandfunc2onalinyourfirearm.

Pleaseunderstandonlyyouareul2matelyresponsibleforwhatyouchoosetoproduceandfireinarifle.Iwillneverfiresomeoneelse’shandloadedammoinmyfirearm.Trustprofessionalshereyoursafetydependsonit.

Thesinglebestsourceofknowledgetoproducehandloadedammuni2onisnotme!

Surprised?

Welldon’tbe,thesinglebestsourceisapublishedreloadingmanualproducedbyoneofthemajorpowderorbulletcompanies;Nosler,Sierra,Speer,Hornady,orHodgdonpowder.Thefirstfewchaptersinthebookarededicatedtotheverydetailsthatwillallowyoutosurvivewithallyourfingersandeyeballs.Detailedstepsintheprocesswillbeoutlined;ashowtosetupthesizingandsea2ngdies,andothernecessaryequipment,allthingsthatareproceduralandIwillnotcoverhere.Themanualwillalsocoverdescrip2onsandpicturesofsafeandunsafeloadpressuresigns,allmannerofvaluableinforma2onthatyouhavenobusinessacquiringfromanareaotherthanthatpublishedbyprofessionals,whousedlabsandtestequipment,thatyouraverageshooteronSocialmediahasnoideaexists.Consultoneofthesepublica2onsifyouarenewtohandloadingammuni2on.

Afewofthemanualstheauthorkeepsonhandandconsultswithregularly.

Selec5ngapowderandchargeweightcanbeaccomplishedusingpublishedloaddatafromareputablesource,suchasbulletorpowdercompanies,industryexperts,orthegeneralconsensusofagroupofpeoplewhentheoutliersaredisregarded.I’llbetyouarescratchingyourheadonthatlastone,letmeexplain.Ifyoujoinasocialmediaforumorfacebookgroupandaskaques2onsuchas,“whatthebestloadina6.5x47Lapuawith140grainbullets”Youarelikelytoget20responses.Lookatalltheresponsesandyouwillfind10ofthoseguysarerecommendingthesamebulletandreallyclosetothesamepowdercharge.Soif10guyssaya140Bergerhybridwith36.0to36.9grainsofVargetpowder,withthebullet.030”offthelands,thatwouldgiveyouapre]ygoodplacetostart.If1guysays37.9grainsofpowder,heisanoutlierandalthoughthatmightbeasafeloadinhisindividualrifledoesnotmakeitsafeinyours.Foryourpurposedisregardhisinforma2on.Ifyougoofftheconsensusofagroupofpeopledoali]lefollowupresearchwiththepowdercompaniesandmakesureyouareinthevicinityofasafeload.Ul2matelyyoursafetydependsonsolidinforma2on,industryprofessionalsarealwaysthebestsourceofreloadingdata.

Typically2or3powderswillbeshinningstarsforapar2cularcartridge,ifyouaregoingtouseWinchester748becauseyourdadgaveyou16lbs.ofitandyouwanttouseitup….WellwhatcanIsay?Walkawayfromthisar2cleitisnotforyou.

Soideallywefoundaloadfromoneof3differentsources,nowweneedtofigureouthowthatpertainstoourrifle.Firstweneedto“findthelands”Thisisbestaccomplishedwithatoolthatadaptstoyourpar2cularcartridgethatallowsyoutotakeoneofyourbulletsandgaugethelandsinyourchamberandgetameasurementoftheOAL(overalllength)ofyourcartridgewherethebullettouchesthelands.TypicallyagreatruleofthumbistostartloadingyourcartridgeswithanOALthatputsthebullet.030”offthelands.Thisallowsthebulletto“jump”slightlybeforeengagingthelandswithoutcrea2ngadangerouspressurespike.Thisiswhyitiscri2caltohaveaworkingknowledge(there’sthatwordagain)ofreloadingtools,measuringinstruments,andthebasicterminologyofreloading,whichcanallbefoundinagoodhardcopyreloadingmanual.

Withthisinforma2onIamreadytoassemblemycartridge,usingtheinforma2onandknowledgethatIacquired,Iamgoingtostartwithapowderchargeonthelowendoftherecommenda2on.SointhiscaseIgleanedthatthechargesbetween36.0and36.9ofVargetworkedformanyshooters.SoIwillstartonthelowsideandbecertainthechargeisgoingtobesafeinmyrifle.

Ipersonallycallthese“break-inloads”.Inanynewhandlappedbarrel,veloci2esproducedtendtoclimbaswegetabout100-150roundsfiredthruthenewbarrel.Sopriortodoinganyseriousloadadjustmentswewanttoletthisprocesshappen.Why?Wellahandlappedbarrelgoesthruastabilityprocesswheretheveloci2esapar2cularloadproducesmaybeslightlyerra2cforaperiodof2measthebarrelwearsin.thisisohenreferredtoas“barrelbreak-in”Whichsomeshootermisunderstandasaprocesstheyperformbycleaning,wheninfactitisaprocessthathappensregardlessofwhatyouphysicallydotothebore.Ifwedevelopaloadinthefirst20roundsfired,thatloadwillohenbeoutoftunebythe2mewehit150roundsfiredandcanohenbeoverpressuredfromtheincreaseinfric2oncausedbythebarrelbreakinprocess.

InmyriflesItypicallyload150breakinroundsatastar2ngloadcharge,andjustusethemupinbarricadeprac2ce,orproneshoo2ngwhileIworkonmyfundamentalsofmarksmanship.Theseloads

areohenveryaccuratebutmayjustnotbetoyourdesiredspeedrangeyouexpect.That’sfine;wearejustlookingtogetthrutheprocessofstabilizingourbarrel.IhaveonoccasionusedtheseloadsinlocalonedaymatcheswhenIwasshorton2me.TypicallyItryandcleanmyriflesboreonceaherabout20roundsandthenoncewhenallbreakinroundshavebeenused.

Theauthorchecksthecaseheadsa<erfiringanewtestloadforsignsofexcessivepressure.TheprimersarenotoverlyflaAenedandwiththeexcepBonofthefarrightcasethereisno“brassswiping”fromtheejectorplunger.YetyearsofexperiencetellstheauthorthisloadisatwhatheconsidersamaxloadbasedonthatoneliAleshinnyspotbetweentheGandAofGAP.The chargeweightwasreducedby.4grainsofpowderwhichtookawayabout40FPSfortheauthorsworkingmatchload.

DeterminingourMatchLoad;

Sonowthatwehaveastabilizedbarrelandarereadytodetermineourfinalloadforthisriflewecanaccessourbreakinloadandohentweakittoaccommodateourdesiredresults.Sinceweshot150roundsweshouldhave3thingsaccomplished.A100yardzeroonourrifle,avelocityreadyingonthelast5or10loadswefired,andanaccuracybenchmarkthatitperformedwiththatammuni2on.

ThisparBcularbreakinloadwasveryaccurateintheauthor’s6.5x47Lapuarifle,butwasnotinthevelocitywindowhedesired,somefinetuningofthepowderchargewillbeneededtogetthisloadabovethe2690feetperseconditproduced.(group1)

Iftheaccuracyandspeedareacceptableyouarefinished.Ifthespeedisnottothetypicalspeedofthe6.5x47Lapua(generally2720-2780fpswitha140grainbullet26”barrel)thenwecanaddpowdertothecasein.2grainincrementsun2lwereachourdesiredspeedwindow.

InthecaseoftherifleIamusingasanexampleandthepicturesaccompanyingthisar2clewecanseethe“group1”photothatmyaccuracywasacceptablebutthespeedwasabitslowforthewindowIwanttobein.Thepar2cularbreakinloadrequiredtheaddi2onof.9grainsofVargetforachargeweightof36.9grainsofpowdertoachieveavelocitythataveraged2775feetpersecond.

Theresultswithnootherchangesresultedinthe2ghteningofthegroupbasedsolelyonthechargeweightalone.Thisiswhatisreferredto“chargeweightloadtuning.”Becausetheloadwassoaccurate,therewasnoneedto“sea2ngdepthtunetheload”whichisohenthecasewithmanybulletsandcartridgesthatIstartat.030”offthelands.Istart.030”offforareason,becauseitworksin90%ofmyrifles.Thisiswhereexperiencema]ers.Yourexperiencewillgrowasyoudevelopsolidreloadinghabits.

Thefinalloadof36.9grainsofVarget,.030”offthelandswitha140grainBergerHybridwasclearlyveryaccurateinhiscustomcompeBBonrifle.(group2)

Let’ssaythisloaddidnotproducetheaccuracywedesiredbutitdidproducethevelocitywewereseeking.Whatwewouldwanttodothenischangeoursea2ngdepth,andreshoottheloadsforaccuracy.AnexamplewouldbeImayloadup5roundseachat.020”,.040”,.050”,.060”,.070”offthelandsusingthesamechargeweightof36.9grainsofVarget.Ialreadytested.030”offsohaveareferencethere.Idonotwanttoseatanycloserthan.020”offthelandsbecauseIneedammuni2onforriflematchesthatfunc2onsandfeedexcellentwithnoboltclosingissuesorthepossibilitythatanunfiredroundmaybeejectedandleavethebulletstockinthebore,causingamalfunc2on.

Ahershoo2ngthesedifferentsea2ngdepthsyoumayno2ceoneshotbe]erthantherest.Thatisgreatwearemakingprogress.Ifthatloadiss2llnottoyouraccuracydesireyoucannowtrytochargeweighttunethatloadagainatthesea2ngdepthwefound,typicallythiswillendyourloaddevelopmentasyoushouldhavesomethingthatmeetsyourstandards.

Thisisnottheonlywaytoproduceaccurateloads,butitisthewayIdevelopmyrifleloadsonthe100yardrangeIhaveaccessto.WhenpossibleIwillconfirmver2calspreadonadifferentshoo2ngrangefrom800-1000yards.

WhatismyStandard?

Notallrifleandammuni2onbulletcombina2onswillshootaswellasthegroup2photo.InallhonestyforPrecisionRifleMatches,group1wouldbealoadIwouldbeextremelyhappywith.Ifyouconstantlytrytweakingyourloadyouareactuallygoingbackward.Frustra2onovernotgelngsupersmallgroupsisgoingtocausepoormatchresultsfromalackofconfidencewhichiscompletelymiss-directed.Yourriflesaccuracyrarelywinsmatches,yourconfidence,calmnessandconsistentshoo2ngwinsmatches.

Whatifmyriflewilljustnotshootthisloadatall?Thisisveryrareinwell-builtcustomriflesusingqualitycomponentsandchamberedintargettyperiflesusinggoodammuni2on.Ihavea4stepprocessforcorrec2ngordiagnosingthecause.

FirstIcheckallmyfasteners,ac2onscrews,scoperingsandbases,andtriggerclearancewiththebo]ommetalortriggerguard.IbasicallyeliminateasmanymechanicalvariablesasIcan.

SecondIswitchtoadifferentbulletanyqualitybullet.BCisnotimportantasIamjusttryingtodetermineifmyoriginalbulletchoiceissuspect.

ThirdItryadifferentpowderwithmyoriginalbullet,rarelythiswillbetheproblembutoccasionallyithasmadeallthedifference.

ForthItrysomequalityfactorytargetammuni2onintherifle,toexcludemeasthehandloaderfromsomethingImaybedoingwrongintheprocessbutcompletelyoverlooking.

Forthisacalltothegunsmith,hemaywanttoinspecttherifleforanyissuesandohen2mesknowswhattolookforandisfullycapableofdiagnosingtheproblem.Ifyouareapprehensiveaboutcallingyourgunsmithyouprobablypickedthewrongmantobuildyourrifleinthefirstplace.Weareheretomakesureourcustomersriflesareshoo2ngandwanttohelp.

Accuracyproblemsinaonceaccuraterifle;

Ihavehadacoupleofbarrelsinthelast20orsocomeupshoo2ngpoorlyaherafewhundredrounds.Againfirstcheckthemechanicsofthesystemforanythingloose,cleantherifleofcopperandcarbonfouling,especiallyifithasbeen500roundsormoresinceyourlastcompletecleaning.Don’tforgettoinspectandcleanamuzzledevice,ohen2mescarbonbuilduponthecrownorthebafflesofabrakecanopengroupsup.Occasionallysomebulletscomeoutoftuneandtheloadneedstobeadjustedinsea2ngdepthorpowdercharge,ifthatisthecasetrychasingthelandsorincreasingyourpowderchargejustslightly.

Thecarbonsbuildupinthismuzzlebreakcausedgroupsizestodoubleinthisrifle.

Asafinalwordofcau2on,nevertryandchasespeed.Thatextra50-100fpsyouaretryingtogetoutofyourrifleisnotgoingtomagicallycauseyoutouselesswindandhitmoretargets.Insteaditwillcauseyouamul2tudeofpossibleproblems,toincludepoorbarrellife,poorbrasslife,inconsistentaccuracy,andeventualfeedandfunc2onproblemsattheworstpossible2me,andworstofallthepoten2alforinjury.

Thankyoufortakingthe2metoreadthis2partseriesonloaddevelopmentfortheprecisionrifle.Iclearlycouldhavemadethisa10partseriesanddovemuchdeeperintothesubject,butbarringthe15daysIwouldhavespentonsuchanar2cle,thisisagoodintroduc2onintothesimpleprocessIusewhichhasservedmewell.Ihopesomeofthe2psandinstruc2onherehasbroadenedyourknowledgeonthesubject,andpeakedyourinterestinhandloadingyourownammuni2on.

Bio;JimSeehasbeenshooBngcompeBBvelyandbuildingcustomriflessince2008,heownsEliteAccuracyLLCandconBnuestoshootprecisionriflematches,instructsincompeBBontrainingclassesandbuildcustomrifles.