AR Bolt Carriers interchangeable with different uppers? Is it okay to use the same bolt carrier group on a new barrel?
Bolt carrier groups (BCGs) are not typically interchangeable between different firearms. Each BCG is specifically designed for a specific platform, and as such, most will not fit into other types of guns. In addition, even if a BCG does physically fit into another platform, it may not function correctly due to differing operating specifications. For example, AR-15 and AR-10 platforms use different-sized BCG meaning that one cannot be used in the other without modification. Lastly, we must consider caliber when discussing BCG interchangeability. bolt carrier groups are created for specific cartridges therefore trying to use a 6.5 Creedmoor BCG in a 5.56 firearm will result in disaster. To sum it up, it’s generally not a good idea to try and mix and match different bolt carrier groups between firearms.
