Carbine, Caliber 5.56 mm, M4 Type Assault rifle Carbine Place of origin United States Service history In service 1994–present Used by See Users Wars See Conflicts Production history Designed 1982–1993 Manufacturer See Manufacturers Unit cost $700 (avg. cost)[1] Produced 1987–present[2] No. built 500,000[3] Variants See Variants Specifications Mass 6.43 lb (2.92 kg) empty[4] 7.75 lb (3.52 kg) with 30 rounds and sling Length 33 in (838 mm) (stock extended) 29.75 in (756 mm) (stock retracted)