Study Unit Ammunition, Reloading, and Basic Ballistics

106 Pages·2003·3.25 MB·English

by  Martin A. Devine

Study Unit
Ammunition, Reloading,
and Basic Ballistics
By
Dean A. Grennell
and
Carl P. Wood
This sneak preview of your study material has been
prepared in advance of the book's actual online release.
About the Authors
DeanA.Grennell’sloveoffirearmsbeganinhisyouth.Fortunately,hisloveofwriting
beganthenalso.Deanbecameinterestedinreloadingjustafterhedecidedtowrite.Since
1948,hehascomealong,longway.Overtheyears,hehaswritten,compiled,andcon-
sultedinvariouscapacitiesformanypublishersandmagazines.Deanhascontributed
articlestovirtuallyeveryAmericangunmagazineanddigestworthyofmention.
You’llrememberCarlP.WoodastheauthorofthestudyunitentitledRifles.
Alltermsmentionedinthistextthatareknowntobetrademarksorserv-
icemarkshavebeenappropriatelycapitalized.Useofaterminthistext
shouldnotberegardedasaffectingthevalidityofanytrademarkor
service mark.
Copyright © 1998 by Education Direct, Inc.
Allrightsreserved.Nopartofthematerialprotectedbythiscopyright
maybereproducedorutilizedinanyformorbyanymeans,electronicor
mechanical,includingphotocopying,recording,orbyanyinformation
storageandretrievalsystem,withoutpermissioninwritingfromthecopy-
rightowner.
Requestsforpermissiontomakecopiesofanypartoftheworkshouldbe
mailedtoCopyrightPermissions,EducationDirect,925OakStreet,Scran-
ton,Pennsylvania18515.
Printed in the United States of America
iii
Preview
Thisstudyunithastwomainparts.Thefirstcoverscartridgenomenclature,design,andreload-
ingproceduresformetalliccartridges.Thesecondcoverssimilaraspectsofshotshellreloading.
Theunitalsocontainsmuchrelevanthistoricalinformation,aswellasinstructionforanyone
interestedinpurchasingreloadingequipment,figuringoptimumpowderloads,and/orcasting
bullets.
Whenyoucompletethisstudyunit,you’llbeableto
(cid:1)
Recognize ammunition and component nomenclature and design
(cid:1)
Identify reloading tools and explain their purposes
(cid:1)
List reloading procedures for metallics and shotshells
(cid:1)
Explain bullet casting procedures
(cid:1)
Discuss the importance of basic ballistics in determining optimum loads
v
Contents
INTRODUCTION TO RELOADING. . . . . . . . . . . . . . . . . . . . . . . . 1
CartridgesandCartridgeCases
Primers
SeatingPrimers
ReloadingPressesandEquipment
THE RELOADING PROCESSES. . . . . . . . . . . . . . . . . . . . . . . . . . 21
SettingUpforReloading
TheStepsofReloading
POWDERS AND RELOADING TOOLS . . . . . . . . . . . . . . . . . . . . . . 35
NotesonReloadingTools
EquipmentManufacturers
SupportingEquipment
SmokelessPowders
PowderManufacturersandSuppliers
BULLETS AND BALLISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
BuyingBullets
CastingBullets
CastingAlloys
CastingTemperatures
SwagingBullets
Ballistics
BallisticCoefficient
LoadDataandInformationSources
WildcatCartridges
ShotloadsforHandguns
UnsuspectedHazards
SHOTSHELL RELOADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Introduction
FlexibilityofShotshellReloading
DamascusBarrels
HistoryofShotshells
ShotshellReloadingMachines
ChargeBarsandBushings
AdjustablePowderBars
ShotshellComponents
TheReloadingProcedure
SteelShot
Patterns
SlugLoads
ZERO IN! ANSWERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
EXAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
vii
Important Safety and Health Precautions
Note: AlthoughthefollowingsafetyandhealthprecautionsmakespecificreferencetotheAlliant
Techsystemslineofpowders,theypertaintoreloadingsafetyingeneral.Therefore,weintroduce
themasaprefacetothisstudyunit.
Toperforminagun,powdersmustigniteeasilyand Herculespowdercontainsnitroglycerin,whichcould
burnrapidly.Thesecharacteristicsrequireuseofcom- enterthebodythroughingestionorabsorption,orby
monsensetoavoidaccidents. O M STO S breathingthevapors.Symptomscanincludehead-
T FO OWI P CA TIO S. aches.Therefore,thefollowingprecautionsmustbe
observedwhenhandlingHercules powders:
1. Do notsmoke when reloading.
1. Do nottake internally. In case of ingestion,
2. Do notuse spark-producing tools.
cause vomiting by putting finger down throat.
Call physician.
3. Do notmix powders of different kinds.
2. Prevent contact with food, chewing material,
4. Do notleave powder where children can get it.
and smoking material.
5. Do nottry to load when distracted.
3. Have adequate ventilation during handling.
6. Avoid an open fire or working near spark-
4. Washhandsandfacethoroughlyafter handling.
producing machinery.
5. Do notcarry powder in clothing.
7. Pour out only the amount of powder needed for
immediate work.
Youmustalsoalwaysremember:
8. Check the powder measure each time it is used.
1. Establish a routine for reloading. It will result in
Make sure the settings have not been acciden-
more uniform loads and less chance of error.
tally changed. Check-weigh “thrown charges”
frequently. 2. Some primers are more powerful than others
(they produce more gas at a higher tempera-
9. Clean up any spilled powders. Use a brush and
ture). Use only the primers specified herein.
dustpan;do notuse a vacuum cleaner.
3. Shotshell wads differ in their sealing ability.
10. Store powder only in its original Hercules con-
Use only the load combinations specified
tainer, which was carefully designed for this
herein.
usage.Do notREPACKAGE.Do notpurchase or
accept any Hercules powder not in its original, 4. If you use cast bullets, their diameter, hardness,
FACTORY-SEALED container. lubrication,andcrimpwillallaffecttheballistics.
11. Be sure the powder container is completely 5. The shotshell loads in this booklet are for use
empty before discarding.Do notuse the con- with lead shot only!
tainer to store other powders or materials, or
6. Use only the brands of powder and components
for any other purpose.
shown in our tables.Do notsubstitute other
12. Keep always in mind that Hercules smokeless types.
powder is an explosive material and highly
SafetyandHealthPrecautionscourtesyofAlliant
flammable. It should always be stored and han-
Techsystems,Radford,VA
dled in such a way as to avoid impact, friction,
heat, sparks, or open flame.
13. Wear safety glasses when reloading.
1
Ammunition, Reloading, and Basic Ballistics
INTRODUCTION TO RELOADING
Cartridges and Cartridge Cases
Thecenterfireprimermakesreloadingpossibleandpractical.There’s
nopracticalwaytoreloadfiredrimfirecases,suchasthefamiliar.22
LongRifle(Figure1).Fornow,we’lldiscussreloadingofthemetallics,
meaningammunitionforuseinhandgunsand/orrifles,withcover-
ageofreloadingshotshellstofollow.
FIGURE 1—You can’t reload
rimfire ammunition, such as
the familiar .22 Long Rifle,
as there’s no way to get
priming compound into the
hollow rim around the case
head.
Wecustomarilyrefertoaloadedroundofmetallicammunition,
readytobefiredinahandgunorrifle,asacartridge.Theprojectileup
frontisthebullet.TheBritishtendtocallthecartridgeabulletandthe
projectileabullethead.
Reloadingoffersmanyattractiveadvantages,oneofwhichiscash
savings.Oneofthemostexpensivecomponentsofacommercialcar-
tridgeisitscase.Thecaseremainsonhandafterfiring—unlessan
autoloadinggunejectsitintothickbrushortallgrass.Youcanreload
atypicalemptycenterfirecaseseveraltimes.Inaddition,reloading
providesasourceofcartridgeswithspecificationsthatarenotavail-
ablethroughtheusualcommercialsources.Bytryingvariouscombi-
nationsofbulletsandpowdercharges—andmaintainingcareful
records—youmaybeabletoisolateloadsthatdelivertightergroups
thanfactoryammunition.Youcanalsogainagooddealofpersonal
gratificationwhenareloadyou’veassembledturnsinanuncom-
monlygoodperformance(Figure2).
2 Ammunition, Reloading, and Basic Ballistics
FIGURE 2—One of the ad-
vantages of reloading is
the possibility of saving
money over the factory
ammunition, which can
cost substantially more.
Thecartridgecase,customarilyformedfrombrass,assumescertain
basicshapes.Theseshapesaremoreorlessdictatedbythegunsfrom
whichtheyfire.Forexample,theremaybeadistinctflangeorrimat
thehead,astypifiedbythefamiliar.30-30WCF,orWinchesterCenter
Fire(Figure3).Cartridgesdesignedforuseinautoloadinggunsusu-
allydispensewiththerimforthesakeofeasyfeeding.However,they
stillneedsomethingfortheextractortograbinordertopullthespent
casefromthechamber.Suchcartridgesusearimlessdesign,withthe
headthesamediameterastherearofthecaseandanextractorgroove
turnedinthehead,asillustrated.Typicalexamplesincludethe.30-06
Springfield,.308Winchester,and.45ACP(AutomaticColtPistol).
Afurthervariationisthesemirimmed,similartotherimless,butwith
theheadflangeslightlylargerindiameterthanthecasebody.Exam-
plesincludethe.220WinchesterSwiftandthe.38Super(Figure4).
The.284Winchesterrepresentsstillanotheroffshoot(Figure5).Ithas
atypicalrimlessheadwiththebasicdimensionsofthe.30-06Spring-
field,butthecasebodyissomewhatlargerindiameter.Asyoumight
suspect,there’sareasonbehindsuchcomplexities.Inthisexample,
thepurposeistoprovideacomparativelyshortcase,withagreater
powdercapacity,capableofbeingusedinrifleswithboltfacesdi-
mensionedtotakethecommonandpopular.30-06Springfield.A
similarapproachisthe.41AE(ActionExpress)foruseinautoloading
pistols.Ithasheaddimensionsidenticaltothe9mm(millimeter)
Luger,butthebodyofthecaseisenlargedtoacceptbulletsof.410
inchdiameter,upfront.The.50AEhastheheaddimensionsofthe
.44Magnumandacasebodylargeenoughtoworkwithbulletsof
.510inchdiameter.Wesaythecartridges,suchastheexamplesjust
mentioned,havearebatedrim.
Ammunition, Reloading, and Basic Ballistics 3
FIGURE 3—The .30-30
Winchesterisanexample
of a rimmed rifle case
and the .30-06 Spring-
field is a rimless rifle
case.
FIGURE 4—From left,
a .357 Magnum is a
rimmed-type case,
the .38 Super is a
semirimmed, the .45
ACP is a rimless, and
the .41 Action Express
has a rim smaller in
diameter than the body
of the case, a rebated-
head design.
Thetermmagnumhasbecomewidelyused—andsometimesmisused—
incartridgeterminology.Itmeansbiggerthancustomaryandorigi-
nallyreferredtooversizedwinebottles.Atsomepointalongtheway,
acartridgedesignercrankedinaconcepttermedthebeltedmagnum
casehead.Itstartsoutlookinglikeastandardrimlessheadbut—as
opposedtotherebatedhead—atapointjustaheadoftheextractor
cut,thecasediameterisslightlyenlarged(Figure6).
4 Ammunition, Reloading, and Basic Ballistics
FIGURE 5—The .284 Win-
chester is another example
of the rebated-head case
design.
FIGURE 6—This 7mm
Remington Magnum is
an example of the
belted magnum case
head design.
Thatbringsupheadspace,atermthattendstobemystifyingwhen
initiallyencountered.Headspaceistheamountoffore-and-aftplay
availabletothecartridgewhenchamberedandreadytobefired.
Whenthefiringpinslamsintotheprimer,thecartridgemustbe
supportedtoremainmotionless,ratherthanbeingdrivenbodily
downthebarrel.
Thepurposeoftheseveraldifferenttypesofcartridgecasedesigns
istoprovideheadspacingsupportinthechamber.Theyalsoassistin
thechamberingofthecartridgeandextractionofthefiredcase.
Somecartridgeshavestraightcases,suchasthe.45ACPor.38Special,
withthecasewallsparallel.Others,suchasthe9mmLugerand.30
GICarbine,havestraightcasewallsthattaperslightlyfromheadto
mouth(Figure7).Manyothersareofthebottleneckdesign,witha
fairlylarge-diametercasebehindataperingshoulder,withthecar-
tridgenecksubstantiallysmallerindiameter.Afamiliarexampleis
the.223Remington,alsoknownasthe5.56mmNATO.
Ammunition, Reloading, and Basic Ballistics 5
FIGURE 7—The .30 M-1
Carbine and 9mm Luger
have straight-sided
cases that taper slightly
from head to mouth.
Thepurposeofthebottleneckcaseistoprovideroomformorepow-
derbehindthebullet,withoutexcessivecaselength.Atthesame
time,thebottleneckprovidesheadspacingsupportbycontactbe-
tweenitsshoulderandthematingchamberarea.Theprimaryhead-
spacingsupportcomesfromtherimorbeltofthebeltedmagnum
designs.Contactbetweentheshoulderandchambergivesamore
preciseanduniformsupport,allofwhichcontributetothepotential
accuracyofthecartridge/riflecombination.
Instraight-sidedcaseswithrims,therimprovidestheprincipalsup-
port.It’sapopularbeliefthattheheadspaceofrimlesscartridges,
suchasthe.45ACP,isbycontactbetweenthecasemouthandmating
ledgeinthechamber.Actually,theextractorprovidessome(ifnotall)
ofthesupportforthe.45ACP.
Primers
Variouschemicalcompoundswillexplodeordetonatewhenstruck
andcompressedabruptly.Shootersusedoneoftheearliestexamples,
fulminateofmercury,astheprimingcompoundformuzzle-loading
gunswhosepowderchargeswereignitedbypercussioncaps.