5.56mm Cartridge M193 NATO 5.56mm ball cartridge. There are currently five 5.56mm cartridges in service.

History

In the mid 1950s testing was begun on finding a lighter replacement for the Winchester .308 (NATO 7.62mm) infantry rifle cartridge used by the in the M-14 rifle. Eventually three cartridges were select for further testing; the .222 Special, .224 Springfield, .222 Winchester. All were essentially lengthened versions of the recently introduced .222 Remington. Eventually the .222 Special was adopted and re-designated as the .223 Remington. The .223 Remington was introduced, along with the Armalite AR-15 Assault rifle, for experimental use by the Army in 1957. In 1964 the cartridge was officially adopted by the U.S. Army as the M193 5.56mm ball for use in the M-16 rifle (which was, itself, based on the Armalite AR-15.

Description

There are currently five 5.56mm cartridges in service.

M193 NATO 5.56mm ball cartridge: Introduced in 1964, the M193 was the original 5.56mm cartridge designed for use in the M-16 rifle with a 1 in 12 rifled barrel twist. No longer in production, but still in stock, it has been replaced by the heavier M855 cartridge. The M193 can be identified by its unpainted (copper) tip.

M855 NATO 5.56mm ball cartridge: Introduced as a replacement for the M193 cartridge, the M855 fires a heavier projectile with greater accuracy. While the cartridge was designed to be fired from the newer heavy barreled M-16A2 assault rifle and M-4 carbine (each of which has a 1 in 7 twist barrel) it may be fired out of older M-16 models without severe degradation of accuracy. The M855 can be identified by its green painted tip.

M856 NATO 5.56mm ball/tracer cartridge: Introduced with the M855, the M856 is the tracer variant of the M855. It is, in all respects, identical to the M855. The M856 can be identified by its orange painted tip.

M200 NATO 5.56mm blank firing cartridge: Designed for use with training simulators, the M200 has no projectile and contains a reduced powder charge. The M200 can be identified by its crimped and sealed cartridge opening in place of a projectile.

M862 5.56mm Short Range Training Ammunition: Designed for indoor use, the M862 is a restricted range alternative to the M193/M855 cartridge. With a maximum range of 250 meters and an effective range of 25 meters, the M862 serves as an excellent low cost substitute for Basic Rifle Marksmanship (BRM) training. The M862 can be identified by its blue plastic tip.