Series of individual 1/1,000,000-second exposures showing shotgun firing shot and wadding separation
Two rounds of .357 Magnum, a centerfire cartridge; notice the circular primer in the center
Vincent Hancock in the men's skeet finals at the 2008 Summer Olympics
Comparison of centerfire and rimfire ignition
A Gurkha Contingent trooper in Singapore armed with a folding stock pump shotgun
The primer of this unfired cartridge has been sealed with red lacquer to prevent oil or moisture from reaching the powder charge and priming explosive.
An American marine fires a Benelli M4 shotgun during training in Arta, Djibouti, 23 December 2006
Berdan (left) and Boxer (right) primed rifle cartridges.
Confederate cavalryman
Large (top row) and small (bottom row) pistol cartridge Boxer primers. (L–R fired, unfired, and inside view.) The tri-lobe object inside the primer is the anvil.
A United States Marine carrying a Winchester M97 shotgun during World War II
The same cartridge (.45 ACP shown here) can have different primer sizes depending on manufacturer.
A view of the break-action of a typical double-barrelled shotgun, shown with the action open
A fired pistol case as indicated by the dimple from a firing pin and a shotgun (right) primer against an inch and mm scale.
A Winchester M1897, one of the first successful pump-action shotgun designs
A modern reproduction of the Winchester M1887 lever-action shotgun
Closeup of MTs255
A Browning A-5 semi-automatic shotgun
A United States Army soldier armed with a Mossberg 500 shotgun
Bond Arms Cowboy Defender .45 Colt/.410 Shotshell Derringer
U.S. Marines fire their shotguns
Loading 12-gauge shells
Two rounds of Fiocchi 12-gauge rubber buckshot
A homemade lupara
A RCMP officer in 2010 armed with a shotgun outfitted to fire beanbag rounds
Barack Obama skeet shooting with a Browning Citori 525 on the range at Camp David

The majority of today's handguns, rifles, and shotguns use centerfire ammunition, with the exception of a few .17 caliber, .20 caliber, and .22 caliber handgun and rifle cartridges, small-bore shotgun shells (intended for pest control), and a handful of antique (and mostly obsolete) cartridges.

- Centerfire ammunition

Usually a drilling containing more than one rifled barrel would have both rifled barrels in the same caliber, but examples do exist with different caliber barrels, usually a .22 long rifle and a centerfire cartridge.

- Shotgun
Series of individual 1/1,000,000-second exposures showing shotgun firing shot and wadding separation

3 related topics

Alpha

A modern round consists of the following: 1. bullet, as the projectile; 2. cartridge case, which holds all parts together; 3. propellant, for example gunpowder or cordite; 4. rim, which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired; 5. primer, which ignites the propellant.

Cartridge (firearms)

Type of pre-assembled firearm ammunition packaging a projectile , a propellant substance (usually either smokeless powder or black powder) and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting.

Type of pre-assembled firearm ammunition packaging a projectile , a propellant substance (usually either smokeless powder or black powder) and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting.

A modern round consists of the following: 1. bullet, as the projectile; 2. cartridge case, which holds all parts together; 3. propellant, for example gunpowder or cordite; 4. rim, which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired; 5. primer, which ignites the propellant.
A variety of rifle cartridges: (1).17 HM2 (2).17 HMR (3).22LR (4).22 Win Mag R/F.22 WMR (5).17/23 SMc (6)5mm/35 SMc (7).22 Hornet (8).223 Remington (9).223 WSSM (10).243 Win (11).243 Win Improved (Ackley) (12).25-06 Remington (13).270 Winchester (14).308 Win (15).30-06 Springfield (16).45-70 Government (17).50-90 Sharps
Three straight-walled cartridges (9×19mm Parabellum, .40 S&W and .45 ACP) on the left, three bottleneck cartridges (FN 5.7×28mm, 5.56×45mm NATO and .300 Winchester Magnum) in the center, and two polymer-cased 12-gauge shotshells on the right.
Smokeless powders used for handloading
A large portion of the energy generated by the propellant is released as a muzzle blast and a bright flash, instead of transferring to the projectile
Percussion caps, the precursor of modern primers
Comparison of primer ignition between centerfire (left two) and rimfire (right) ammunitions
Flash hole profiles on Berdan (left) and Boxer (right) primers.
0.30–30 Winchester case, stages in the drawing process, book; from Hamilton
US Cartridges 1860–1875 
(1) Colt Army 1860 .44 paper cartridge, Civil War 
(2) Colt Thuer-Conversion .44 revolver cartridge, patented 1868 
(3) .44 Henry rim fire cartridge flat 
(4) .44 Henry rim fire cartridge pointed 
(5) Frankford Arsenal .45 Colt cartridge, Benét ignition 
(6) Frankford Arsenal .45 Colt-Schofield cartridge, Benét ignition
Historic British cartridges
Chassepot paper cartridge (1866).
(From Left to Right): A .577 Snider cartridge (1867), a .577/450 Martini-Henry cartridge (1871), a later drawn brass .577/450 Martini-Henry cartridge, and a .303 British Mk VII SAA Ball cartridge.
French Army Fusil Gras mle 1874 metallic cartridge.
The 8 mm Lebel ammunition, developed in 1886, the first smokeless gunpowder cartridge to be made and adopted by any country.
Fired rimfire (left) and centerfire (right) cartridges. A rimfire firing pin produces a notch at the edge of the rim; a centerfire pin produces a divot in the center of the primer.
Schematic of a rimfire cartridge and its ignition
Slow motion shots (1/1,000,000-second exposures) showing shots and wadding separation after firing from a shotgun.
A 12-gauge Brenneke slug
Two views of intact bean bag round and one view of the projectile
A cutaway showing a Japanese Navy 7.7 mm rimmed rounds as fired by the Type 92 and Type 97 machine guns—copies of Vickers and Lewis designs. The round is effectively interchangeable with .303 British.
A variety of common pistol cartridges. From left to right: 22 LR, .22 WMR, 5.7×28mm, 25 ACP, 7.62×25mm Tokarev, 32 ACP, 380 ACP, 9×19mm Parabellum, 357 SIG, 40 S&W, 45 GAP, 45 ACP, .38 Special, 357 Magnum, 45 Colt
CCI .22LR snake shot loaded with No. 12 shot
An example of caseless ammunition. This disassembled round, the 4.73×33mm, is used in the Heckler & Koch G11 rifle.
Dardick 1500 with trounds
Blank cartridges:
23×152mm cartridge, drill round
9 × 19 mm Mek-Porek
An assortment of snap caps of varying calibers
Rimless .380 ACP semi-automatic cartridge
Rimmed .38 special revolver cartridge

Cartridges can be categorized by the type of their primers – a small charge of an impact- or electric-sensitive chemical mixture that is located: at the center of the case head (centerfire); inside the rim (rimfire); inside the walls on the fold of the case base that is shaped like a cup (cupfire, now obsolete); in a sideways projection that is shaped like a pin (pinfire, now obsolete); or a lip (lipfire, now obsolete); or in a small nipple-like bulge at the case base (teat-fire, now obsolete).

The main defining component of the cartridge is the case, which gives the cartridge its shape and serves as the integrating housing for other functional components – it acts as a container for the propellant powders and also serve as a protective shell against the elements; it attaches the projectile either at the front end of the cartridge (bullets for pistols, submachine guns, rifles, and machine guns) or inside of the cartridge (wadding/sabot containing either a number of shot or an individual slug for shotguns), and align it with the barrel bore to the front; it holds the primer at the back end, which receives impact from a firing pin and is responsible for igniting the main propellant charge inside the case.

A US Navy sailor fires a Mk 18 Mod 1 carbine at a target.

Firearm

Any type of gun designed to be readily carried and used by an individual.

Any type of gun designed to be readily carried and used by an individual.

A US Navy sailor fires a Mk 18 Mod 1 carbine at a target.
A Colt Single Action Army revolver, with hammer cocked back
A Glock 17 semi-automatic pistol
Springfield Armory M1903 rifle
A US Marine firing a Mossberg 500 shotgun
MG 42 general-purpose machine gun with retracted bipod
The Accuracy International Arctic Warfare series of sniper rifles is a standard issue in the armies of several countries, including those of Britain, Ireland, and Germany (shown).
Czechoslovak 7.65 mm submachine gun Škorpion vz. 61 designed in 1959.
Suomi M31 submachine with a 70-round drum magazine attached, 20- and 50-round box magazines.
The AK-47 is one of the most widely produced and used assault rifles in the world.
FN P90 PDW
Belgian FN SCAR-H
Hand cannon from the Chinese Yuan Dynasty (1271–1368)
The istinggar, a result of Indo-Portuguese gun-making traditions
A) The matchlock gun with button for trigger, which came to Lisbon from Bohemia, used by the Portuguese until the conquest of Goa in 1510. B) The Indo-Portuguese matchlock gun resulted from the combination of Portuguese and Goan gunmaking. C) The Japanese matchlock gun appeared as a copy of the first firearm introduced in the Japanese islands.
A musketeer (1608)
Hand cannon being fired from a stand, "Belli Fortis", manuscript, by Konrad Kyeser, 1400
Percussion cap and early bolt action form
Various Japanese (samurai) Edo period matchlocks (tanegashima)
A wheellock pistol mechanism from the 17th century
Flintlock mechanism
(From left to right): A .577 Snider cartridge (1867), a .577/450 Martini-Henry cartridge (1871), a later drawn brass .577/450 Martini-Henry cartridge, and a .303 British Mk VII SAA Ball cartridge.
The French FAMAS, example of a bullpup rifle
The M4 carbine, a modern-day service rifle capable of being fired automatically. It is in service by the U.S. military and has a wide ability for customization.
Gun-related homicide and suicide rates in high-income OECD countries, 2010, ordered by total death rates (homicide plus suicide plus other gun-related deaths).

Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stability.

The primer charge is at the base of the cartridge, either within the rim (a "rimfire" cartridge) or in a small percussion cap embedded in the center of the base (a "centerfire" cartridge).

The toggle-link action used in the iconic Winchester Model 1873 rifle, one of the most famous lever-action firearms

Lever action

Type of action for repeating firearms that uses a manually operated cocking handle located around the trigger guard area that pivots forward to move the bolt via internal linkages, which will feed and extract cartridges into and out of the chamber, and cock the firing pin mechanism.

Type of action for repeating firearms that uses a manually operated cocking handle located around the trigger guard area that pivots forward to move the bolt via internal linkages, which will feed and extract cartridges into and out of the chamber, and cock the firing pin mechanism.

The toggle-link action used in the iconic Winchester Model 1873 rifle, one of the most famous lever-action firearms
Spencer-carbine M1865, .50 inch
Colt-Burgess rifle
Colt Paterson Ring Lever rifle
Inside of Marlin 39A receiver
Savage Model 99 rifle
A modern reproduction of the Winchester Model 1887 lever-action shotgun
M1895 operating mechanism showing the lever in the forward (top) and rear (bottom) positions
Henry rifle, toggle-lock

Most lever-action firearms are rifles, but some lever-action shotguns and a few pistols have been made.

Mossberg produces the Mossberg model 464 in centerfire .30-30 and rimfire .22.