Battle Arms Development AR-15 / M16 Full Auto Bolt Carrier Group

Upgrade your next upper receiver build with the Battle Arms Development® AR-15 / M16 Full Auto Bolt Carrier Group. The bolt carrier is machined from billet 8620 heat-treated steel and features a nitride corrosion-resistant coating for an ultra-hard, low-friction surface that provides smooth operation and makes cleaning easy. The bolt is heat-treated 9310 steel and features a corrosion-resistant nitride finish. Plus, the bolt is shot peened and is magnetic particle inspected. The gas key is properly staked and features 4140 steel construction with a corrosion-resistant nitride coating and the firing pin is 8640 steel and hard chrome plated. The cam pin is 4140 hardened heat-treated steel with a corrosion-resistant nitride finish. Finally, the extractor is 4140 billet steel with a corrosion-resistant phosphate finish. Extractor insert and Viton O-ring included.