Standard military rifle cartridge for NATO forces. Civilian .223 Remington is similar but with lower chamber pressure. Extremely popular for AR-15 platform.
Type: Rifle
Introduced: 1980, United States
Parent case: .222 Remington Magnum
Standardization: NATO
Bullet diameter: 0.224" (5.69 mm)
Case length: 1.76" (44.7 mm)
Overall length: 2.26" (57.4 mm)
Max pressure: 62,000 PSI
Rim type: Rimless
Primer: Small Rifle
Typical twist rate: 1:7 to 1:9
Muzzle velocity: 2750–3240 fps
Muzzle energy: 1200–1400 ft-lbs
Effective range: 600 yd
Common bullet weights: 55, 62, 69, 77 gr
Primary use: Military, Target, Competition, Varmint
Production status: Active
Also known as: 5.56 NATO · 5.56x45 · SS109 · M855
History: Developed in late 1950s by Remington and Eugene Stoner for the AR-15. Adopted by US military in 1964 for M16 rifle. Standardized by NATO in 1980. Civilian .223 Rem introduced in 1962.
Notable firearms: M16, M4 Carbine, AR-15, HK416, SCAR-L, Steyr AUG
Military use: {"country":"United States","years":"1964-present","conflicts":["Vietnam War","Gulf War","Iraq","Afghanistan"]}, {"country":"NATO","years":"1970s-present"}
Similar cartridges: .223 Remington, .22 Nosler