One of Bushmaster's most popular Carbine models, the M4 type features a distinctive military barrel profile and a six position telestock that makes it great for 3 gun match shooting, home defense and law Enforcement use. The Bushmaster A2 & A3 Type Patrolman's Carbines are modeled after the M4 Carbines, but with additional barrel length to make them legal for sale to individuals. The 5.56mm/.223 Rem. caliber 16" 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. A mil. spec. manganese phosphate outer coating insures protection against corrosion or rust on the barrel and all critical steel parts of the weapon.