Caliber Explanation

8/9/2019 Caliber Explanation

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CaliberFrom Wikipedia, the free encyclopedia

"Calibre" redirects here. For other uses, see Calibre (disambiguation).

This article includes a list of references, but its sources remain unclear

because it has insufcient inline citations. Please help to improe this

article by introducing more precise citations. (September 2014)

From left! .# $%&, .'## Win %ag, .'# Winchester, .*+'- mm, .* mm

/0T1, .++23

0 . cal 0CP hollo4point (Federal 56T) 4ith t4o .++ 23 cartridges for comparison

http://en.wikipedia.org/wiki/Calibre_(disambiguation)http://en.wikipedia.org/wiki/Wikipedia:Citing_sourceshttp://en.wikipedia.org/wiki/Wikipedia:Citing_sources#Inline_citationshttp://en.wikipedia.org/wiki/Wikipedia:WikiProject_Fact_and_Reference_Checkhttp://en.wikipedia.org/wiki/Wikipedia:When_to_citehttp://en.wikipedia.org/wiki/.50_BMGhttp://en.wikipedia.org/wiki/.300_Winchester_Magnumhttp://en.wikipedia.org/wiki/.308_Winchesterhttp://en.wikipedia.org/wiki/7.62%C3%9739_mmhttp://en.wikipedia.org/wiki/5.56%C3%9745_mm_NATOhttp://en.wikipedia.org/wiki/5.56%C3%9745_mm_NATOhttp://en.wikipedia.org/wiki/.22LRhttp://en.wikipedia.org/wiki/Hollow-point_bullethttp://en.wikipedia.org/wiki/Federal_Cartridgehttp://en.wikipedia.org/wiki/.22_LRhttp://en.wikipedia.org/wiki/File:22-45.jpghttp://en.wikipedia.org/wiki/File:Rifle_cartridge_comparison.jpghttp://en.wikipedia.org/wiki/Calibre_(disambiguation)http://en.wikipedia.org/wiki/Wikipedia:Citing_sourceshttp://en.wikipedia.org/wiki/Wikipedia:Citing_sources#Inline_citationshttp://en.wikipedia.org/wiki/Wikipedia:WikiProject_Fact_and_Reference_Checkhttp://en.wikipedia.org/wiki/Wikipedia:When_to_citehttp://en.wikipedia.org/wiki/.50_BMGhttp://en.wikipedia.org/wiki/.300_Winchester_Magnumhttp://en.wikipedia.org/wiki/.308_Winchesterhttp://en.wikipedia.org/wiki/7.62%C3%9739_mmhttp://en.wikipedia.org/wiki/5.56%C3%9745_mm_NATOhttp://en.wikipedia.org/wiki/5.56%C3%9745_mm_NATOhttp://en.wikipedia.org/wiki/.22LRhttp://en.wikipedia.org/wiki/Hollow-point_bullethttp://en.wikipedia.org/wiki/Federal_Cartridgehttp://en.wikipedia.org/wiki/.22_LR


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6ide on ie4 of 6ellier 7 $ellot .8cal 0CP cartridge 4ith a metric ruler for scale

In guns, particularly firearms, caliber or calibre is the approximate internal diameter of the barrel, or the diameter of the projectile it fires, usually shown in millimeters, or in hundredths or

thousandths of an inch. When expressed in inches in writing or print, it is shown in terms of a

decimal fraction: .45 caliber, for example. When the barrel diameter is given in inches, theabbreviation cal can be used. !or example, a small"bore rifle with a diameter of #.$$ inches

can be called a .$$ or a .$$ cal% however, the decimal point is generally dropped when spo&en,

ma&ing it a twenty"two caliber or a two"two caliber rifle. When caliber is expressed in

millimeters, this is noted, as in, 'mm pistol.

In a rifled barrel, the distance is measured between opposing lands or grooves% groove

measurements are common in cartridge designations originating in the (nited )tates, while land

measurements are more common elsewhere. *ood performance re+uires a bullet to closely

match the groove diameter of a barrel to ensure a good seal.

While modern cartridges and cartridge firearms are generally referred to by the cartridge name,

they are still lumped together based on bore diameter. !or example, a firearm might be described

as a .-# caliber rifle, which could be any of a wide range of cartridges using a roughly .-#"in projectile% or a .$$ rimfire, referring to any rimfire cartridge using a .$$"cal projectile.

!irearm calibers outside the range of ./ to .5# 04.5 to $./ mm1 exist, but are rarely

encountered. Wildcat cartridges, for example, can be found in .#, .$, and .4 cal 0$.5, -.#, and

-.2 mm1, typically used for short"range varmint hunting, where the high"velocity, lightweight bullets provide devastating terminal ballistics with little ris& of ricochet. 3arger calibers, such as .

5//, .55, .2##, ./##, and ./$' 04./, 4.', 5.$, /., .5 mm1 are generally found in

proprietary cartridges chambered in express rifles or similar guns intended for use on dangerous

game.67 8he .'5# 99 is the only &nown cartridge beyond ./' caliber used in a rifle.

In some contexts, e.g. guns aboard a warship, caliber is used to describe the barrel length as

multiples of the bore diameter. ; 5"inch 5# calibre gun has a bore diameter of 5 in 0$./ cm1

and a barrel length of 5# times 5 in < $5# in 02.-5 m1.

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Caliber (artillery)From Wikipedia, the free encyclopedia

This article includes a list of references, but its sources remain unclear

because it has insufcient inline citations. Please help to improe this

article by introducing more precise citations. (April 2010)

3elationship of caliber in bore and length of gun.

In artillery, caliber or calibre6nb 7 is the internal diameter of a gun barrel, or by extension a

relative measure of the length.

Rifed barrels

=ifled barrels introduce ambiguity to measurement of caliber. ; rifled bore consists of alternating

grooves and lands. 8he distance across the bore from groove to groove is greater than thedistance from land to land. >rojectiles fired from rifled barrels must be of the full groove to

groove diameter to be effectively rotated by the rifling, but the caliber has sometimes been

specified as the land to land diameter before rifling grooves were cut. 8he depth of riflinggrooves 0and the conse+uent ambiguity1 increases in larger calibers. )teel artillery projectiles

may have a forward bourrelet section machined to a diameter slightly smaller than the original

land to land dimension of the barrel and a copper driving band somewhat larger than the grooveto groove diameter to effectively seal the bore as it becomes enlarged by erosion during

prolonged firing. (nited )tates ?avy guns typically used rifling depth between one"half and one

percent of caliber. >rojectile bourrelet diameter specification was #.#5 inches 0#.- mm1 less

than land to land diameter with a minus manufacturing tolerance so average clearance was about

#.#$ inches 0#.-# mm1. riving band diameter was groove to groove diameter plus #.#$ inches0#.5 mm1.67

Barrel length

8he length of the barrel 0especially for larger guns1 is often +uoted in calibers. 8he effectivelength of the barrel 0from breech to mu@@le1 is divided by the barrel diameter to give a

dimensionless +uantity. ;s an example, the main guns of the Iowa"class battleships can be

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referred to as 2A5# caliber. 8hey are 2 inches in diameter and the barrel is ## inches long 02

B 5# < ##1. 8his is also sometimes indicated using the prefix A3% so for example, the most

common gun for the >an@er C tan& is described as a /5 mm A3/#, meaning a barrel with aninternal bore of /5 mm, and 5,$5# mm long 0/ ft $.2' in1.

8he bore to barrel length ratio is called caliber in naval gunnery, but is called length in armyartillery. Defore World War II, the () ?avy used 5A5 caliber 05A351 as surface"to"surface

guns and 5A$5 caliber 05A3$51 as surface to air guns. Dy the end of World War II, the dual purpose 5A- caliber 05A3-1 was standard naval armament against surface and air targets. ;ll

three had a bore diameter of 5 inches 0not 5.5 or 5.$5 or 5.- as often misread1.

?aval rifles, although constructed and manufactured in roughly the same manners as land basedartillery, were built to much more stringent and studious standards than land based weapons, and

for good reason. ;t sea, a weapon had to perform, without fail. 8here was no ready replacement,

nor one that could be readily supplied. Ever time, the terms of pound 0weight of shell1 and bore

0the actual bore of the weapon1 became confused and blurred. Fventually, when the technology

existed, the bore 0in inches or millimetres1 came to be the standard measure. !or naval rifles, theinitial change was to actual bore, thus facilitating the manufacture of standard projectiles. 8hey

then began to measure the effective length 0and therefore range1 of the weapon in calibers. 8hesewere 0and are1 a measure of the standardi@ed bore of the barrel versus the rifled bore of the

barrel. In other words, a $A45 is $G45< the length of the rifled bore of that gun in inches. 8his

explains the differences in both peneration and long range performance of various naval riflesover the years. In addition to the possible improvements in overall performance 0i.e. mu@@le

velocity and stri&ing force1, the increase in barrel length also allowed, in some circumstances, an

increase in projectile si@e as well. !or example, the ;merican 4A45, as introduced in the New

York "class battleships, fired a $5# lb. projectile. 3ater improvements to the design, lengtheningthe rifle itself and also altering the breech, allowed a 4## lb. projectile and, overall, a greater

barrel life. ;gain we see this pattern with the () 2 guns. 8he initial design was 45 calibers inlength and fired a $$## lb. shell. 8he later re"design to 5# calibre not only allowed a highervelocity but also a heavier $/## lb. shell, which ultimately came to be accepted as the greatest

naval shell ever deployed in combat.6$76-7647657

Farly gun barrels were short and thic&, typically no more than $2 calibers, as the gunpowder

propellant they used burned very +uic&ly and violently, and hence its acceleration time was short.)lower"burning brown powder formulations of gunpowder allowed gun barrel length to

increase slightly in the #s but enormous +uantities of brown powder were re+uired. ?ew

slower"burning smo&eless powder propellants available from the #s onwards such as>oudre D, cordite and nitrocellulose allowed a gentler prolonged acceleration, hence gun barrels

were made progressively longer and thinner. 8he new formulations were far more powerful

propellants than gunpowder and far less was needed by weight as they transformed almostentirely to gasses when burned. Hu@@le velocity became limited only by the length of barrel that

was feasible, both in terms of the construction methods of the day and in terms of any practical

constraints imposed by the guns manner of use.

8he practical effect of long barrels for modern guns is that the projectile spends more time in the barrel before it exits, and hence more time is available for expanding gas from the controlled

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burning of the propellant charge to smoothly accelerate the projectile, bringing about a higher

velocity without placing undue strain on the gun. In internal ballistics terms, if the base of a

projectile is thought of as a piston propelled by the expanding gas, then as barrel length increasesthe volume swept by the piston also increases, and hence the amount of energy that can be

extracted from the gass burning increases. ; longer barrel allows more propellant to be used: the

propellant is all burned fairly early in the projectiles journey along the barrel, but the projectilecontinues accelerating as long as the gases generated as a result of the burning continue to exert

pressure on its base.627 8his pressure is reduced by the increasing barrel volume the gas has to fill,

and in order to achieve maximum mu@@le velocity with the shortest barrel length, the projectileshould exit the barrel as the gas pressure reduces to a small fraction of the maximum.

8echnological improvements had made it possible to introduce into use long gun barrels that are

strong enough to withstand the forces involved in accelerating the shell to a high velocity, while

remaining light enough to be reasonably mobile, rigid enough to maintain accuracy, and having a bore able to withstand many firings before needing refurbishment. In World War I 45"caliber

naval gun barrels were typical, in World War II 5#" to 55"caliber barrels were common, with

*ermany already manufacturing tan& guns of /# calibers by '4-. 8oday 2#" to /#"caliber barrels are not uncommon, but the latest technology has allowed shorter barrels of 55 calibers to

attain mu@@le velocities of 5,/## feet per second 0,/## mAs1, as with the =heinmetall $# mm

tan& gun.

owever, as many such guns fire projectiles which are much smaller than the gun bore, usingdiscarding sabots so the relationship of projectile si@e to barrel length is not as straightforward as

with older ordnance.


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!or example, .$$ short refers to a .$$ caliber cartridge with a short case and a light powder

load. Ether options of such .$$ caliber rimfire cartridges include .$$ long, .$$ long rifle 03=1,

and .$$WH= 0magnum1. ; .$$ 0caliber1 rifle chambered for .$$3= is commonly 0but notalways1 able to shoot the short, rifle and long"rifle cartridges.

8he case of the magnum is both longer than the others and has a diameter somewhat greaterthan the actual projectile diameter, so the magnum cartridges will not fit in a gun chambered for .

$$3=""and these cartridges produce considerably greater energy and projectile speeds.

8he words magnum and super in caliber designations always mean more projectile energy

than for cartridges without the word. 8he .-5/ magnum is a caliber for a cartridge that is

closely the same as the .- special except for the fact that its case is longer and contains moregun powder, and therefore produces greater projectile energy than the .- special. 8he .-

special is the caliber for the revolver that was long the standard weapon for police and for

civilian self protection. It and the .-5/ magnum are still much used in this manner.

; .-5/ magnum revolver can shoot .- special cartridges in addition to the mag cartridges.8his is done often for target practice because the smaller cartridges are cheaper and dont &ic&

as hard. 8he .-5/ magnum is also used for hunting by people who li&e to give the animal more

of a chance than they would get from a hunter with a rifle 0the handgun hunter has to get closer,

because the handgun is not as accurate as a rifle1.

; cartridge with a very slightly smaller outside diameter than the .- special is the .-# auto for

automatic and semiautomatic handguns. 8he .-# cartridge case is shorter than that of the .-

special and holds less powder, so the cartridge does not produce as much energy as the .-special.

)ome of the inch calibers mentioned earlier generally refer only to cartridges for automatic orsemiautomatic handguns. !or example, the .$5 and .-# are common calibers for such handguns

but not for revolvers. Ethers calibers are common only for revolvers 0li&e .- special and .44magnum1. !or some, however, there are cartridges for both types of guns. ;n example is .45

Jolt for revolver and .45 ;J> for automatic and semiautomatic. !or some numerical

designations there may be several different calibers differentiated by the appended

word0s1Aabbreviation.

.$$- is a small caliber originally developed for warfare. .$/# Winchester is a commonly

used big"game hunting caliber. !or some numerical designations, again, there are several

different calibers that are differentiated from each other with word modifiers of several types.

8here are also numerous rifle calibers that are identified with usually a two digit decimal number followed by a dash or a slash, then another number. Fxamples: .$$"$5# =emington, .-#".-#

Winchester, .$5A#2 =emington and .-#"#2. 8he meanings of these second numbers are not

consistent. !or the -#"aught"six the #2 refers to the year of invention, '#2.

METRIC DESIGNATIONS FOR CALIBER


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andgun calibers are commonly identified as something li&e 'mm 3uger or #mm. 8hese

both are cartridges for automatic and semiautomatic handguns.

?umbers li&e /.2$x--mm are metric designations for rifle calibers. 8his one is a calibere+uivalent to the .-# caliber carbine cartridge. 8he /.2$ is the diameter of the projectile in

millimeters. 8he --mm is the length of the cartridge case. ;nother example is /x5/mmHauser.

SHOTGUN AND SHOT SHELL GAUGE DESIGNATIONS

Ene shotgun guage, the .4#, is a decimal inch designation for inside barrel diameter 0i.e., thebore1. Ether guage designations are different. 8here are # guage, $ guage, 2 guage and $#

guage. 8he larger the number, the smaller the barrel inside diameter. 8he numbers are the

numbers of spherical lead balls""of diameters e+ual to the inside diameter of the gun""that arere+uired to total up to a pound of lead. 8he greater the barrel inside diameter, the fewer balls are

re+uired to ma&e the pound.

What is Caliber? Bullet Sizes Explained

clic& to enlarge 0download >!1

KouLve heard it on your favorite cop show, Mloo&s li&e the &iller used a twenty"two,N or, Mhe was&illed with a nine millimeter.N Dut, if youLre curious li&e I was, youLre as&ing yourself, Mwhat the

hec& is a twenty"two and what does it mean anywayON

Well, common sense would suggest that the numbers have something to do with si@e and that is

exactly correct. When you hear various numbers being mentioned related to bullets, the number

being referred to is whatLs called the bulletLs “caliber”. Jaliber is a unit of measurement relatedto a bulletLs si@e. )pecifically, whatLs being described is the bulletLs diameter.

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clic& to enlarge 0download >!1

8o be even more specific, the caliber of a bullet is the measurement of the diameter of the slug0or projectile1 part of the bullet cartridge. 8his is important because in some situations, the bullet

casing will be wider than the slug itself. Dut the caliber is specifically describing the width of the

slug portion. Jaliber does not refer to the length or power of the bullet 0in most cases1, butsimply the diameter of the bullet.

The Bottom Line The Width o! a Bullet "etermine#s $ts Caliber

I &now, youLre thin&ing, Mbut whatLs a twenty"two compared to a nine millimeterON Well, as with

all measurements, thereLs the ;merican way and the Hetric way of measuring. 8he metric issimple, a nine millimeter 0'mm1 is 'mm in diameter. 8he ;merican measurement is a little

different. ; twenty"two 0or #.$$1 is twenty"two one hundredths 0$$A##Ls1 of an inch in diameter P or a little less than a +uarter of an inch. )imilarly, a #.44 is 44A##Ls of an inch, a .5# caliber isa half inch, and so on.

Upate

;s ILve been corrected and corrected again, the MinchesN measurements are considered part of the

MImperial )ystemN of measurement instituted by *reat Dritain and retained by some of herformer colonies P the most prominent of which is the (.).;. )o, we have metric measurement in

millimeters and the Imperial measurement in inches.

Clari!icatio"s

;s a few have commented below, I want to point out two things in how this page refers to bullet

caliber:

!irst, this page is about bullet caliber, not gun caliber. I ma&e that distinction because a gun

designed to fire a 'mm bullet may have a barrel with an internal diameter slightly larger than

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'mm 0for example '.##$mm1. 8hat doesnLt change the fact a gun referred to as a 'mm handgun

does fire bullets that are designated as 'mm rounds.

)econdly, ILm not necessarily encouraging anyone to grab a caliper and actually measure thediameter of a bullet to determine itLs caliber. 8he point of this web page is to explain how bullet

calibers have been derived and the names they continue to bare as well as how to most easilycompare them to each other. 8o that end, I feel compelled to point out that It is, in fact, actually

extremely common for bullets to be referred to by a cailber number that is ?E8 the actualdiameter of the bullet. !or example, the bullet found in a cartidge referred to as a .- )pecial is

?E8 actually #.- inches in diameter. Kou can learn more about that specific round here.

)o, just to clarify for everyone: bullet caliber refers to the diameter of the slug portion of theentire bullet cartridge. EWFCF=, the number of the caliber may be slightly smaller or larger

than the actual measured diameter of that slug. Fach round has its own uni+ue history and

perhaps weLll explore and explain those some day on this site. Dut, after being critici@ed for not

clarifying those potential and common imperfections in caliber designation I wanted to ta&e the

opportunity to explain it here. I hope that this explanation sufficiently covers that.

8han&s, again, to everyone who contributes to this page and site.

0mmunition 9:planation

This site is pretty great for those of us 4ho don;t get 4hy a is bigger - but a '#

is so freaking tiny but completely di


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=t is ery dangerous to Bre ammunition of the 4rong sie for your gun. %ost Brearms

hae the correct caliber stamped on the side of the barrel or frame. =f yours does

not, don;t simply guess at the correct ammunition sie. Take the gun to a gunsmith

or to the gun store from 4hich you purchased it, and hae an e:pert measure your

Brearm;s chamber.

&enerally speaking, caliber refers to the sie of the bullet a gun 4ill Bre, and also

usually refers speciBcally to the bullet;s diameter or to the bore sie of the gun that

Bres it. $ut due to all sorts of agaries in the ammunition8manufacturing 4orld, the

nominal caliber designation isn;t al4ays the actual bullet diameter or chamber

measurement. /or is the bullet diameter the only factor that matters, as 4e 4ill see

in the discussion belo4.

6ometimes caliber is measured on the imperial scale, by decimal fractions of inches.

1ther times it is measured on the metric scale, usually in millimeters. =n either case,

the Brst number you see isn;t al4ays all the information you need to discoer in

order to kno4 if the ammunition 4ill 4ork in your gun.

6ometimes, instead of one simple number, the ammunition sie and type 4ill be

represented by t4o groups of numbers. =n such cases, the Brst number usually

indicates the bullet diameter, 4hile the second number often (but not al4ays)

represents the length of the cartridge, measured from base to case rim.

Caliber numbers are usually follo4ed by 4ords or letters to create the complete

name of the cartridge. These letters often represent a brand name or an

abbreiation for the name of the company that Brst introduced the round, or gie

more information about the length of the cartridge. These letters are as importantas the caliber number. =n most cases, it isn;t enough to kno4 the initial numbers.

Dou;ll need to kno4 the letters 4hich follo4 them as 4ell.

$elo4 follo4s a 4hirl4ind tour of some common calibers and cartridges. =t is not a

comprehensie list, merely a >uick oerie4 of some caliber8related facts 4hich

might interest a beginning or intermediate shooter.

& 'anduns

& Shotuns

'anduns

5andgun cartridges are relatiely straightfor4ard, compared to the unbelieable

things that the shotgun and riEe ammunition manufacturers hae done to us. $ut

there is still plenty of opportunity to get mi:ed up.

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11/23

1ne important thing to remember about handgun ammunition is that ammunition

designed to be Bred in semi8automatics is generally di


12/23

The .++ 2ong 3iEe and .++ 6hort are both the same diameter.

The .++ Winchester %agnum 3imBre, or .++ W%3, is often called the .++ %agnum or

.++ %ag in casual speech. The .++ %agnum is slightly larger in diameter than the .

++ 23 or .++ 6hort. The case is also some4hat longer and holds more po4der, giing

the round a little more punch than the .++ 23. =t is used in both riEes and handguns.0 reoler chambered for .++ %agnum 4ill physically accept a .++ 23 round, but

these are diue to

handguns. =f you;re looking for a defense round, stay a4ay from this one. 0lthough

>uite common in cheap handguns, it really isn;t po4erful enough to do 4hat you

need it to do.

1f the .+ 0uto, Brearms great @e< Cooper once famously >uipped, "... carry a + if

it makes you feel good, but do not eer load it. =f you load it you may shoot it. =f you

shoot it you may hit somebody, and if you hit somebody 8 and he Bnds out about it 8he may be ery angry 4ith you."

The .'+ 0CP or .'+ 0uto 4as among the many cartridges deeloped and popularied

by @ohn %oses $ro4ning and the Colt company back around the turn of the last

century. =n 9urope, this round is called the .*mm $ro4ning. Today it is used in

small, light4eight pistols, especially those small enough for pocket carry, but most

Brearms instructors 4ill tell you that .'+ 0CP is not po4erful enough to be used for

dedicated self8defense.

Aesigned for reolers, the .'+ 573 %agnum round 4as introduced in G-'. =t isn;tthe same thing as the .'+ 0CP. 0 handful of Brearms manufacturers produce

reolers chambered for the .'+ 573 %agnum.

The +eally Con!usin 'andun Calibers

.', .', -mm 3ounds

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13/23

With the .'# 0CP or .'# 0uto, 4e enter the realm of truly confusing caliber facts.

3emember that the cartridge numbers often, but not al4ays, indicate the diameter

of the bulletH The .'# 0uto is one of the e:ceptions. =ts bullet actually measures .

'" (-mm) in diameter. $ecause its bullet diameter is -mm, but the oerall length

of the cartridge is shorter than other -mm ammunition, .'# 0CP is sometimes

called the -mm 6hort. 1ther names for it are -mm ?ur (kur means short in&erman), or -mm Corto (Corto means short in =talian). =t;s also sometimes called

the -mm $ro4ning because its inentor 4as @ohn %oses $ro4ning. The .'# 0CP

round is 4idely belieed to be the minimal round acceptable for self8defense, and it

4as the faored police round throughout 9urope for most of the +#th century.

1ood 1rie!2 'o3 4any 5mm Cartrides .re There?

&ood >uestionI &enerally speaking, if you hear someone refer to a -mm, they 4ill

mean the -mm 2uger round.

0nother round in this sie class is the -:Gmm %akaro, often simply called the

-:G. This one 4as pretty rare in 0merica until a fe4 years follo4ing the breakup of

the J663 but has become more familiar to 0merican buyers 4ith the popularity of

%akaro pistols. 2ength4ise, the -:G falls about half4ay bet4een the .'# 0CP

and the more common -mm 2uger, but in terms of performance, it;s most similar to

the .'# 0CP. 0 confusing factoid! although the -:G is called a -mm round, it is

really not -mm. =ts bullet is slightly larger than -mm, measuring .'*" rather than

the -mm8e>uialent .'"

Aespite the incredible number of cartridges 4hich Bre bullets -mm in diameter,

most of the time, 4hen someone refers simply to a -mm, they are talking about the

ery common -mm 2uger round, so named in honor of its inentor, &eorg 2uger.1ther names for this same round are -mm Parabellum, or -mm Para, or -:G-mm,

or -mm /0T1. The -mm 2uger is perhaps the least e:pensie of all self8defense

rounds. =t is more po4erful than the anemic .'# 0CP, but like the .'# 0CP it easily

lends itself to Brearm designs 4hich are small and light enough to carry comfortably.

=t is 4idely used in police 4ork throughout the 4orld, and is one of the most popular

calibers for concealed carry.

$s 06 Super the same as 067 .uto?

/o. These are entirely di


14/23

-:+G. @ust be a4are that it isn;t the same thing as the -mm 2uger.

We still haen;t yet left the realm of the -mm calibers. /e:t up is the .' 6ig, a

young cartridge 4hich 4as Brst introduced in G-- and designed by 6=&03%6 (the

folks 4ho produce 6ig 6auer pistols) in partnership 4ith Federal 0mmunition

company. Created to Bre in semi8automatic handguns, it is intended to mimic theballistic performance of .' %agnum reoler ammunition. Aespite its name, the .

' 6ig does not use .'" diameter bullets, but rather uses -mm K .'" diameter

ones. =t still remains to be seen 4hether .' 6ig is a permanent B:ture on the

defensie handgun market, or ust a Eash in the pan 88 but it does hae an

enthusiastic follo4ing.

.' 6uper 0uto, commonly called simply .' 6uper, 4as introduced in G-+- and 4as

popular for many years. 5o4eer, it 4as steadily diminishing in popularity and

perhaps on the edge of e:tinction 4hen a ne4 shooting sport called =P6C reied it

and gae it a place in history. /o4 it is once again among the most popular

cartridges. The .' 6uper is 4idely used in competition Brearms to proide po4er

nearly e>uialent to a . 0CP, but 4ith the lighter recoil and magaine capacity

more typical of the -mm. Aespite the name, .' 6uper does not Bre bullets .'" in

diameter. The bullets it uses are .'" or .'*" across.

Sa!ety %ote

3eolers designed to Bre .' %agnum can also shoot .' 6pecial ammunition. $ut

it doesn;t 4ork the other 4ay around. 9en though .' %agnum ammunition 4ill Bt

into some older .' 6pecial Brearms, take note!+

+e8ol8ers desined to ,re 06 Special should ne8er be used to ,re 0-9

4anum ammunition

This is because .' %agnum ammunition is much more po4erful than .' 6pecial,

and therefore re>uires a sturdier gun for safety;s sake.

While the .' 6uper is a semi8auto round, .' 6pecial is designed for reolers. =t is

probably the most popular reoler cartridge eer produced, and is easily found in

most parts of the 4orld. Aespite the name, this caliber actually uses .'" bullets.

While any short8barreled reoler may be called a "snubby" by aBcionados, mostfolks immediately think of a .' 6pecial caliber reoler 4hen they hear the 4ord

snubby.

0s 4ith many other rounds, the .' 6pecial comes in standard and Lp ariants.

The .' 6pecial has a long history, 4hich means there are a lot of reolers out

there 4hich 4ere produced to Bre this round in the days before modern metallurgy.

These older reolers are not designed to handle the more po4erful ammunition

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15/23

called Lp (think, plus po4er) 4hich became aailable in the early G-#;s. 0s a

result, older .' 6pecial reolers should Bre only the standard rounds, and steer

clear of ammunition marked Lp. 9en some modern reolers, most notably the

super8light4eight alloys, are not designed to handle large olumes of Lp

ammunition. =f in doubt, read the o4ner;s manual or call the manufacturer before

using ammunition marked Lp.

The nice thing about the .' %agnum round is that reolers designed to Bre it can

also Bre .' 6pecial ammunition. What this means is that gun o4ners 4ho purchase

a .' %agnum reoler 4ill be able to use the less8e:pensie .' 6pecial as a

practice round, 4hile resering the more po4erful and more e:pensie .'

%agnum rounds for self8defense. $e a4are, ho4eer, that repeatedly Bring .'

6pecial ammunition through your .' %agnum frame re>uires a special emphasis

on regular, deep cleaning. 1ther4ise, a ring of lead residue 4ill build up 4ithin the

chambers. =f enough rounds are Bred bet4een e


16/23

:: Calibers

These are all reoler cartridges.

First came the . 3ussian, a ery old cartridge deeloped back in the G#;s by6mith 7ampM Wesson for the 3ussian 0rmy under the cars. =nitially deeloped as a

black8po4der round, it successfully made the transition to smokeless po4der and

today is ery popular for Co4boy80ction 6hooting.

%ote

3eolers designed around the . 6pecial can also Bre . 3ussian. Those designed

around the . %agnum can also Bre both . 6pecial and . 3ussian.

=ntroduced around the turn of the last century, the . 67W 6pecial (commonly

called simply . 6pecial) uses a some4hat longer case than the older 3ussian

round. When carried in a compact reoler, . 6pecial can be a good choice for

concealed carry. 2ike the . 3ussian, . 6pecial is also ery popular in the Co4boy

0ction sports.

"This is a . %agnum, the most po4erful handgun in the 4orld ... Ao you feel lucky,

punkH" Aespite the claim in Clint 9ast4ood;s famous lines, the . %agnum (its full

name is . 3emington %agnum) 4as not and is not the absolute most po4erful

handgun cartridge. =t is, ho4eer, a ery po4erful round and the popular mysti>ue

surrounding it makes it een more so. Though it is an e:cellent hunting round, .

%agnum is really too po4erful to use for self8defense! it is diNcult to shoot rapidly,

and there;s a high possibility of the bullet going straight through the intended targetto hit innocent passersby.

:- Calibers

/o matter 4hat the old guys in the gun shop tell you, . 0uto or . 0CP 4ill not

send an assailant Eying across the room if you hit him in the pinkie Bnger. =t is,

ho4eer, a ery good defense round 4hich makes satisfyingly large holes in the

target.

.C/?

0CP means "0utomatic Colt Pistol." Dou;ll Bnd it used to designate many di


17/23

$ro4ning for the Colt Company around the turn of the +#th century, and has

become one of the most popular and successful rounds eer inented. =n part this is

because of the tremendous continuing popularity of G-GG8pattern pistols designed

to Bre . 0CP. 9en though there are G-GG ariants 4hich Bre other calibers and

een though there are many other handguns designed around the . 0CP

cartridge, the . 0CP and the G-GG pistol are closely linked in the minds of mostshooters.

=ntroduced ust a fe4 years ago, the . &0P or . &lock 4as designed to achiee

similar ballistic performance as the . 0CP, but be Bred from smaller, more

concealable pistols. To achiee this, it uses a some4hat shorter case than the .

0CP. &uns sied for . &0P are thus generally more suitable for shooters 4ith small

hands than guns sied for . 0CP ammunition. 0 fe4 other companies hae picked

up the cartridge and designed Brearms around it, so chances are that it 4ill remain

on the market for at least a 4hile.

0n old round designed for reolers, the . Colt (sometimes incorrectly called the .

2ong Colt) is still popular today. =n fact, it is the oldest centerBre handgun

cartridge still in regular use. =t;s most commonly found at Co4boy80ction games,

but can also be found in seeral more modern reolers. =t is not the same as the .

0CP! the case is longer and has a higher olume, making it potentially a more

po4erful round.

-7 Calibers

The .#" calibers are all outside the realm of reasonable defense 4eapons, mostlybecause of controllability and follo4 up speed. These really aren;t for beginners in

any case.

The only thing it seems necessary to point out here is that the .# 09 (or .# 0ction

9:press) designed for handguns is radically di


18/23

Shotuns

Forget eerything you ust learned about caliber. 6hotguns are diual one pound. =n the

case of a G+8gauge shotgun, a lead ball that e:actly Bts 4ithin the barrel 4eighs

GKG+th a pound. 6o it 4ould take t4ele lead balls the sie of the shotgun;s bore to

e>ual a pound.

+emember

The smaller the gauge number, the bigger the barrel;s internal diameter 4ill be.

Counterintuitiely, the smaller the bore, the more lead balls the same sie it 4ould

take to e>ual one pound. 6o a higher gauge number means the internal diameter of

the barrel is smaller, 4hile a smaller gauge number means the internal diameter of

the barrel is bigger.

Thus, a G+8gauge bore is bigger than a +#8gauge bore.

=n the past, shotguns 4ere made in many di


19/23

shorter, but nothing longer. =f you use a longer shell, it may create too much

pressure for your shotgun to handle.

Shell Lenth

The second most important number you 4ill see on the bo: is the oerall length ofthe shotgun shell. /ot all lengths 4ill feed in all shotguns. The common lengths are

+8'K inches, ' inches, and '8GK+ inches.

The longer the shell, the more shot pellets and po4der it can contain. For this

reason, shotguns 4hich are designed to load a shorter shell should neer be used to

Bre a larger shell, een if the larger shell physically Bts 4ithin the gun. The gun may

not be able to handle the higher pressures a more po4erful ammunition produces.

Shell Type

There are three basic types of shells!

5igh brass shells are shells that hae a brass base 4hich e:tends up the shell body

by about three8>uarters of an inch.

2o4 brass shells are characteried by a relatiely narro4 band of metal around the

base of the shell. 2o4 brass ammunition is generally less po4erful than high brass.

0cti shells are formed entirely of plastic, e:cept for a miniature metal button 4hich

holds the primer in the center of the case head. 0cti shells are useful for hunters

and others 4hose ammunition might get 4et in the Beld, because they are nearlyimperious to rust.

"ram Euialents to

indicate ho4 much po4er the load has. The >uantity of smokeless po4der in the

load is compared to the amount of black po4der that 4ould produce the sameelocity 4ith the same proectile(s).

The higher the dram e>uialent number, the more energy the ammunition has and

the faster the shot 4ill trael do4nrange.

Shot Size


20/23

1kay, here;s 4here it gets a bit more confusing. 6hot sies range from the smallest,

/o. - 4hich is .# inches in diameter, up to ### buckshot at .'* inches in diameter.

Shot

%ultiple pellets contained in the shell and sent do4nrange 4hen the shotgun isBred. /o matter ho4 many pellets there are, shot is pluralied 4ithout adding an ;s;

to the end! "a handful of shot." "The case 4as Blled 4ith O* shot."

Common shot sies are /o. - (.# inches), /o. 8GK+ (.# inches), /o. (.#-

inches), /o. 8GK+ (.#- inches), /o. * (.GG inches), /o. (.G+ inches), /o. (.G'

inches), /o. + (.G inches), /o. G (.G* inches), and $$ (.G inches). Plus, there are

larger pellets classiBed as $$$ (.G- inches), T (.+# inches) and TT (.+G# inches).

Aid = mention it 4as going to get confusingH Those numbers aboe 4ere for plain

old shot. $uckshot is something else again.

$uckshot ranges in sie from the smallest, /o. (.+ inches), to the largest, ###

(.'* inches). The categories bet4een /o. $uckshot and ### $uckshot include /o.

' $uckshot (.+ inches), /o. + $uckshot (.+ inches), /o. G $uckshot (.'# inches),

/o. # (.'+ inches), ## $uckshot (.'' inches) and ### $uckshot (.'* inches).*

What this means is that /o. 6hot is substantially di


21/23

Slu

/ot all shotgun ammunition contains shot. 6ometimes, instead of shot, the shell 4ill

contain a slug. 0 slug is a single, ery large bullet. 6ometimes the slug 4ill hae

riEing on the outside, sometimes not. The slug might be partially encased in a sabot

(pronounced sah8bo), 4hich is a (usually plastic) coering designed to improe the4ay the slug Bts snugly 4ithin the bore.

Exotic .mmunition Types

6hotgun shells can be loaded 4ith nearly anything, ranging from less8lethal types to

types that are most decisiely lethal.

2ess8lethal types include rubber buckshot, bean bags, and pepper balls. These are

each some4hat less likely to kill someone than traditional ammunition, but despite

common perception, it is entirely possible to kill someone any of these. $ecause it is

possible to kill 4ith less8lethal ammunition, shooting someone 4ith this type of

ammunition 4ill usually be treated the same, legally, as shooting them 4ith

traditional ammunition. 2ess8lethal ammunition is most often used by la4

enforcement in situations 4here e:traordinary action is re>uired in order to contain

a riot or subdue a suspect. Aepartment regulations generally re>uire that if less8

lethal ammunition is used, oNcers hae immediately aailable backup 4ho are

ready to Bre 4ith traditional 4eapons. This is because less8lethal ammunition does

not al4ays stop determined criminals. $ecause less8lethal ammunition does not

reliably stop determined attackers, or those 4ho are hyped up on drugs, less8lethal

ammunition is not recommended for self8defense use.

6ome shotgun cartridges are loaded 4ith Eechettes instead of shot. Flechettes are

small, steel, pointed dart8like proectiles 4ith aft stabiliation Bns. Aespite online

mysti>ue, these aren;t best for defense because each Eechette has a ery lo4 cross

sectional area, and because only a fe4 Eechettes can be loaded into each shotshell.

That makes Eechettes an inferior choice for home defense 4hen compared to

buckshot.

There are other arious e:otic shotshells! incendiary Aragon;s $reath, bird bombs,

ceramic slugs, bolo proectiles, and so on.

%any of the most e:otic shotshells are handloaded by amateurs, rather than coming

from factory production. =t can be ery dangerous to Bre ammunition that someone

else has constructed. =f you 4ant to sample e:otic shotgun loads, try to stay 4ith

factory8produced ammunition.

=ther $n!ormation

http://www.weaponscache.com/forum/glossary/?do=showentry&item=bullethttp://www.weaponscache.com/forum/glossary/?do=showentry&item=borehttp://www.weaponscache.com/forum/glossary/?do=showentry&item=actionhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=bullethttp://www.weaponscache.com/forum/glossary/?do=showentry&item=borehttp://www.weaponscache.com/forum/glossary/?do=showentry&item=action


22/23

There is often other information on the ammunition bo:. %ost helpfully, many

manufacturers 4ill mark their ammunition 4ith a suggested use. =f all the numbers

aboe confuse you greatly, go 4ith the manufacturer;s suggested use. These

markings 4on;t lead you too far astray.

When looking for your Brst practice ammunition, Bnd something marked "light."2ight loads generally hae less po4er in them and 4ill kick less.

0 really good introduction to basic shotgun kno4ledge, including a great deal more

information about shotgun ammunition, can be do4nloaded as a .pdf Ble from

http!KK444.remington.com, at http!KK444.remington.comKpdfsKshotgun.pdf .

%ore detailed information about shotguns, shotgun ammunition, and shotgun use

can also be found on Chuck 5a4kes; site at

http!KK444.chuckha4ks.comKinde:+c.shotguns.htm .

T0$29 1F C1/T9/T6

>ootnotes

G. 6ome single8action reolers (and a fe4 rare double8action types) allo4 the user

to conert a .++ %agnum reoler to Bre .++ 23 ammunition as 4ell. 6uch

conersions are perfectly functional and accurateM the caution aboe applies to

Brearms 4hich are designed solely to Bre .++ %agnum ammunition.

+. %odern .' 6pecial Brearms 4ill not chamber .' %agnum ammunition, and

the .' %agnum round 4as speciBcally designed to preent that possibility.

5o4eer, there are older, ine:pensie .' 6pecial reolers still aailable on the

used market 4hich hae chambers bored all the 4ay through, making it possible to

physically insert a .' %agnum round into these guns. These older Brearms 4erenot designed to cope 4ith the stronger pressure of the modern .' %agnum round.

'. Tamara on TF2 once discussed this in hysterically funny but historically accurate

detail.

. Though it nearly 4as 88 and certainly 4as the most po4erful production round at

the time. 6eeral ne4er production rounds are much more po4erful.

. 0ctually, .G# isn;t a gauge at all. =t;s a simple measurement of bore sie

http://www.remington.com/http://www.remington.com/pdfs/shotgun.pdfhttp://www.chuckhawks.com/index2c.shotguns.htmhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=actionhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=actionhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=LRhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=chamberhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=TFLhttp://www.thefiringline.com/forums/showthread.php?t=55988http://www.weaponscache.com/forum/glossary/?do=showentry&item=borehttp://www.remington.com/http://www.remington.com/pdfs/shotgun.pdfhttp://www.chuckhawks.com/index2c.shotguns.htmhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=actionhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=actionhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=LRhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=chamberhttp://www.weaponscache.com/forum/glossary/?do=showentry&item=TFLhttp://www.thefiringline.com/forums/showthread.php?t=55988http://www.weaponscache.com/forum/glossary/?do=showentry&item=bore


23/23

e:pressed in fractions of an inch. Aid = mention these folks ust lie to confuse

consumersH

*. 6poken aloud, ## $uckshot is called "double8aught buck." 6imilarly, ### $uckshot

is pronounced "triple8aught buck."

. $y the 4ay, heay isn;t the opposite of light 4hen seen on a shotgun ammunition

bo:. 5eay either means there is more shot per shell than one 4ould e:pect, or itmeans the shot is made of an alloy 4hich 4eighs more than plain steel.

9:cept 4here other4ise noted, all articles and images on this 4eb site +##*8+##-

by ?athy @ackson. For permission to >uote, please contact author.

Aisclaimer! The author of this site assumes that you are an adult human being

capable of making your o4n choices and taking responsibility for same. =f you are

not an adult, or are not capable of taking responsibility for your o4n choices, 6T1P.

Ao not read anything else on this site. The author has made a reasonable, good8

faith e

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Caliber Explanation