Shoot a huge range of calibers with this bolt carrier group (bcg) compatible with Rear Charging 5.56, 223, 300 Blackout, and 350 Legend AR-15 uppers or rifles! Bear Creek Arsenal's 5.56/223/300 Blackout/350 Legend bolt carrier groups (BCGs) are Magnetic Particle Inspected (MPI) to ensure high performance. BCA's 5.56/223 BCG is made with durable 9310 Steel and the gas key is also staked from the side for enhanced durability. Use a Bear Creek Arsenal BCG for your next AR-15 build and experience high performance at a lower cost! Specifications: Brand: Bear Creek Arsenal Caliber / Gauge: .223/5.56 NATO/.300 Blackout/.350 Legend Carrier Style: Lightweight Platform: AR-15 Bolt Finish: Parkerized Bolt Material: 9310 Steel Carrier Finish: Black Nitride Gas Key: Staked from the side to increase longevity Magnetic Particle Inspection: Yes {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}}