As American as 45Auto, .223Rem (5.56x45) has been the standard round of the US military for over 55 years. Developed for the original AR-15, .223 Remington has become one of the most popular sporting rounds with shooters and hunters in the United States. This lightweight, high-velocity round lends itself to being chambered with various styles of rifles from bolt action to semi-auto and belt-fed. Technical Specifications Bullet Type: FMJ-BT Weight: 62 grain Muzzle Velocity (feet per second) 3051 Muzzle Energy (foot-pounds) 1280 Ballistic Coefficient (G1) 0,248 Max Powder Pressure Bar (lb/inch2) 58,015 Cartridge Max Length 2.26 inches Cartridge Average Weight 171 grain