Smyth Busters: Can You Mix & Match Bolt-Carrier Groups?
This guide, based on expert instruction from Brownells' Steve and Caleb, details the critical process of checking headspace when mixing and matching AR-15 Bolt Carrier Groups (BCGs). It emphasizes that while many AR-15 parts are standardized, a headspace check using a 'No-Go' gauge is essential to prevent dangerous malfunctions or failures. Proper tool usage and safety protocols are highlighted for ensuring reliable firearm operation.












