Overall length
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The overall length (OAL) of an ammunition
cartridge Cartridge may refer to: Objects * Cartridge (firearms), a type of modern ammunition * ROM cartridge, a removable component in an electronic device * Cartridge (respirator), a type of filter used in respirators Other uses * Cartridge (surname), a ...
is a measurement from the base of the brass
shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...
casing to the tip of the bullet, seated into the brass casing. Cartridge overall length, or "COL", is important to safe functioning of reloads in firearms. Handloaded cartridges and commercially available cartridges for firearms are normally created with a maximum length standardized by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI). A cartridge's overall length may be shorter than the maximum standard, equal to the standard, or sometimes even longer. The maximum overall length is dictated by the need to fit into a box magazine of standard manufacture. For example, the
.223 Remington The .223 Remington (designated as the 223 Remington by the SAAMI and 223 Rem by the CIP) is a rimless, bottlenecked rifle cartridge. It was developed in 1957 by Remington Arms and Fairchild Industries for the U.S. Continental Army Command ...
cartridge, when loaded for use in the
AR-15 An AR-15-style rifle is any lightweight semi-automatic rifle based on the Colt AR-15 design. The original ArmaLite AR-15 is a scaled-down derivative of Eugene Stoner's ArmaLite AR-10 design. The then Fairchild Engine and Airplane Corporatio ...
rifle (or the military's
M16 rifle The M16 rifle (officially designated Rifle, Caliber 5.56 mm, M16) is a family of military rifles adapted from the ArmaLite AR-15 rifle for the United States military. The original M16 rifle was a 5.56×45mm automatic rifle with a 20-ro ...
), has to fit into the removable box magazine for that rifle. This dictates that the cartridge's maximum overall length be no greater than 2.260". However, for competition purposes during off-hand and slow fire prone match stages, the .223 Remington is loaded one cartridge at a time into the rifle's receiver. This allows for the cartridge to be longer than the standardized 2.260" SAAMI maximum overall length. These cartridges can be safely loaded to a length that has the
ogive An ogive ( ) is the roundly tapered end of a two-dimensional or three-dimensional object. Ogive curves and surfaces are used in engineering, architecture and woodworking. Etymology The earliest use of the word ''ogive'' is found in the 13th c ...
portion of the bullet just touching the rifle's lands. Many competitive shooters will make these cartridges 0.005" less than the truly maximum allowable overall length, for the sake of safety. It is desirable for these single-loaded cartridges to have as little bullet jump as possible before the bullet's
ogive An ogive ( ) is the roundly tapered end of a two-dimensional or three-dimensional object. Ogive curves and surfaces are used in engineering, architecture and woodworking. Etymology The earliest use of the word ''ogive'' is found in the 13th c ...
begins to be engraved by the rifle's lands. This minimized bullet jump increases the accuracy of the rifle, all else being equal. This practice of long-loading a cartridge must be adjusted for each individual rifle, since there are variations from rifle to rifle as to how far down the barrel the rifling begins.


References

{{reflist Ballistics