Spikes ST5BG01 Bolt Carrier Group 223 Rem,5.56x45mm NATO Black Phosphate Steel AR-15, M16 Full Auto $134.96
Radian Weapons R0081 Enhanced BCG 223/5.56 NATO AR-15/M16, Case Hardened 9310 Steel Bolt, Case Hardened 8620 Steel Carrier, Black Nitride Finish, 4130 Steel Gas Key $209.11
Spikes ST5BG03 Bolt Carrier Group 223 Rem,5.56x45mm NATO Nickel Boron Steel AR-15, M16 Full Auto $202.50