91702 : AR-15 A3 Upper Receiver Assembly 450 Bushmaster® 20" BBL

Add the hard-hitting punch of the 450 Bushmaster to your Bushmaster lower receiver instantly. AR-type gas operating system drastically reduces recoil for excellent second shot control. Aluminum forearm free-foats the barrel for optimum accuracy. Heavy barrel is hard chrome-lined in bore and chamber for exceptional durability and enhanced features. 1 in 24” twist rifing, optimized for the .450 bullet. Includes 5-round .450 specifc magazine.

• Built on the versatile Bushmaster modular AR upper platform
• Barreled upper receivers can be used on existing AR15-type lower receivers
• Bushmaster 4150 chrome-moly-vanadium steel barrels feature hard-chrome lining in
• both bore and chamber for extended barrel life
• All receivers feature integral brass defectors and hard anodized fnish
• Each assembly is factory headspaced, proofed, test-fred and ready to use
• Forged, lightweight 7075T6 aircraft-quality aluminum receivers incorporate all M16A2 design improvements including cartridge case defector, bolt catch assembly and raised ribs for protection against accidental magazine release