One of the world's most popular military and law enforcement carbine models, the Bushmaster M4 features the distinctive M4 barrel profile and is now available with a hard Cerakote finish for unmatched durability. The Bushmaster A3 Patrolman's Carbine is modeled after their U.S. Military and law-enforcement utilized M4 Carbines, but with additional barrel length to make them legal for sale to individuals. The 5.56mm/.223 Rem. calibered 16-inch barrel is chrome-lined in both bore and chamber for long wear life and ease of maintenance. For control of muzzle flash and muzzle rise in rapid fire, a birdcage type suppressor is factory installed. The stock, pistol grip, and two piece handguards are all molded of strong black thermoset composite material and the handguards are internally shielded against barrel heat build-up. The dual aperture M16A2 rear sight system on the Patrolman's Carbine offers both windage and elevation adjustment calibrated in meters. The rifle weighs just 6.7 pounds and has a 1 in 9 right-handed twist.