How to Clean Your AR15 Bolt Carrier Group Aero Precision shows you how to clean your AR15 Bolt Carrier Group. Find AR15 BCGs here. Related articles My firearm is not cycling properly. (AR15, M5, EPC) How to clean/lube your BCG What Thread Pitch Is my Aero Barrel? Ballistic Advantage Barrel Information My pivot pin spring and detent will not fully seat.