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 How to clean/lube your BCG My firearm is not cycling properly. (AR15, M5, EPC) What Thread Pitch Is my Aero Barrel? My pivot pin spring and detent will not fully seat. Ballistic Advantage Barrel Information