This is our standard Nickel Boron Coated Bolt Carrier Group for the 5.56./.223 caliber. We use a 9310 Vac-Arc steel Bolt over the Mil-Spec Carpenter 158 Bolt because it's stronger and after many test firings and torture tests we've found it to not only last longer but to be more durable. The Nickel Boron coating has a Rockwell hardness between 52-56. This Bolt Carrier Group comes fully assembled and ready to drop into your rifle.

- AR15 and M16 Compatible

- 8620 Steel Carrier Nickel Boron Coated

- 9310 Vac-Arc Steel Bolt Nickel Boron Coated

- 4340 Steel Cam Pin Nickel Boron Coated

- 4140 Steel Gas Key Nickel Boron Coated

- Tool Steel Extractor Nickel Boron Coated

- Shot Peened

- MPI (Magnetic Particle Inspected)

- HPT (High Pressure Tested)

- Gas key staked to Mil-Spec Standards

- Grade 8 Hardened Fasteners

- Extractor Insert with upgraded Crane O-Ring

- Power Spring Kit

- Nickel Boron Coated