A cartridge, also known as a round, is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance 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 convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile.
In firearms terminology, an action is the functional mechanism of a breech-loading firearm that handles the ammunition cartridges, or the method by which that mechanism works. Actions are technically not present on muzzleloaders, as all those are single-shot firearms with a closed off breech with the powder and projectile manually loaded from the muzzle. Instead, the muzzleloader ignition mechanism is referred to as the lock.
In guns, particularly firearms, but not artillery, where a different definition may apply, caliber is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matches that specification. It is measured in inches or in millimeters. In the United States it is expressed in hundredths of an inch; in the United Kingdom in thousandths; and elsewhere in millimeters. For example, a US "45 caliber" firearm has a barrel diameter of roughly 0.45 inches (11.43mm). Barrel diameters can also be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Since metric and US customary units do not convert evenly at this scale, metric conversions of caliber measured in decimal inches are typically approximations of the precise specifications in non-metric units, and vice versa.
A centre-fire is a type of metallic cartridge used in firearms, where the primer is located at the center of the base of its casing. Unlike rimfire cartridges, the centerfire primer is typically a separate component seated into a recessed cavity in the case head and is replaceable by reloading the cartridge.
A rim-fire is a type of metallic cartridge used in firearms where the primer is located within a hollow circumferential rim protruding from the base of its casing. When fired, the gun's firing pin will strike and crush the rim against the edge of the barrel breech, sparking the primer compound within the rim, and in turn ignite the propellant within the case. Invented in 1845 by Louis-Nicolas Flobert, the first rimfire metallic cartridge was the .22 BB Cap cartridge, which consisted of a percussion cap with a bullet attached to the top. While many other different cartridge priming methods have been tried since the early 19th century, such as teat-fire and pinfire, only small caliber rimfire cartridges have survived to the present day with regular use. The .22 Long Rifle rimfire cartridge, introduced in 1887, is by far the most common ammunition found in the world today in terms of units manufactured and sold.
A lever action is a 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. This contrasts to other type of repeating actions such as the bolt-action, pump-action, semi-automatic, fully automatic, and/or burst mode actions. A firearm using this operating mechanism is colloquially referred to as a levergun.
The chamber of a firearm is the cavity at the back end of a breechloading weapon's barrel or cylinder, where the ammunition is inserted before being fired. The rear opening of the chamber is the breech, and is sealed by the breechblock or the bolt.
The .22 Long Rifle, also known as the .22LR or 5.6×15mmR, is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of firearms including rifles, pistols, revolvers, and submachine guns.
A magazine, often simply called a mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun or externally attached. The magazine functions by holding several cartridges within itself and sequentially pushing each one into a position where it may be readily loaded into the barrel chamber by the firearm's moving action. The detachable magazine is sometimes colloquially referred to as a "clip", although this is technically inaccurate since a clip is actually an accessory device used to help load ammunition into a magazine or cylinder.
The .22 Winchester Magnum Rimfire, also known as the .22 WMR, .22 Magnum, .22 WMRF, .22 MRF, or .22 Mag, is a rimfire cartridge. Originally loaded with a bullet weight of 40 grains (2.6 g) delivering velocities in the 2,000 feet per second (610 m/s) range from a rifle barrel, .22 WMR is now loaded with bullet weights ranging from 50 grains (3.2 g) at 1,530 feet per second (470 m/s) to 30 grains (1.9 g) at 2,200 feet per second (670 m/s).
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge.
Sako Limited is a Finnish firearm and ammunition manufacturer located in Riihimäki, Tavastia Proper in southern Finland. It also has owned the Tikka brand of bolt-action rifles since 1983, and is now owned by the Italian firearm holding company Beretta Holding. The name Sako comes from the company's former name Suojeluskuntain Ase- ja Konepaja Oy.
Marlin Firearms is an American manufacturer of semi-automatic, lever-action and bolt-action rifles. In the past the company made shotguns, derringers, and revolvers. Marlin owned the firearm manufacturer H&R Firearms. In 2007, Remington Arms, part of the Remington Outdoor Company, acquired Marlin Firearms. Remington produced Marlin-brand firearms at its Kentucky and New York manufacturing facilities. In 2020, Sturm, Ruger & Co. bought the Marlin business from bankrupt Remington Outdoor Company.
A rim is an external flange that is machined, cast, molded, stamped, or pressed around the bottom of a firearms cartridge. Thus, rimmed cartridges are sometimes called "flanged" cartridges. Almost all cartridges feature an extractor or headspacing rim, in spite of the fact that some cartridges are known as "rimless cartridges". The rim may serve a number of purposes, including providing a lip for the extractor to engage, and sometimes serving to headspace the cartridge.
.17 Hornady Magnum Rimfire, commonly known as the .17 HMR, is a rimfire rifle cartridge developed by Hornady in 2002. It was developed by necking down a .22 Winchester Magnum Rimfire case to take a .17 caliber (4.5mm) projectile. Commonly loaded with a 17 grain projectile, it can deliver muzzle velocities in excess of 775 m/s.
Locked breech is the design of a breech-reloading firearm's action. This is important in understanding how a self-reloading firearm works. In the simplest terms, the locked breech is one way to slow down the opening of the breech of a self-reloading firearm when fired. The source of power for the movement is recoil.
Break action is a type of firearm action in which the barrel(s) are hinged much like a door and rotate perpendicularly to the bore axis to expose the breech and allow loading and unloading of cartridges. A separate operation may be required for the cocking of a hammer to fire the new round. There are many types of break-action firearms; break actions are universal in double-barreled shotguns, double-barreled rifles, combination guns, and are commonly found in single shot pistols, rifles, shotguns, including flare guns, grenade launchers, air guns, and some older revolver designs. They are also known as hinge-action, break-open, break-barrel, break-top, or, on old revolvers, top-break actions.
Hunting weapons are weapons designed or used primarily for hunting game animals for food or sport, as distinct from defensive weapons or weapons used primarily in warfare.
The 5 mm Remington Rimfire Magnum or 5 mm RFM is a bottlenecked rimfire cartridge introduced by Remington Arms Company in 1969. Remington chambered it in a pair of bolt-action rifles, the Model 591 and Model 592, but this ammunition never became very popular, and the rifles were discontinued in 1974. About 52,000 rifles and 30,000 barrels for the T/C Contender pistol were sold during its brief production run. Remington discontinued the cartridge itself in 1982, leaving owners with no source of ammunition.
The following are terms related to firearms and ammunition topics.
