The Role of the Bolt Carrier Group The bolt carrier group is the heart of your AR-15, AR-10, or pistol caliber carbine. It handles the intense pressure, heat, and carbon buildup generated with every round. A reliable BCG ensures smooth cycling, consistent extraction and ejection, and overall rifle reliability. When a BCG underperforms, it leads … Continue reading Standard BCG vs. Cryptic Coatings BCG: Is the Upgrade Worth It?