Building a 300 Blackout AR-15 is appealing for its simplicity. Unlike other caliber conversions, it only requires swapping out the barrel, thanks to the modularity of the AR platform. The rest of the upper receiver components, including the bolt carrier group, remain the same, as the 300 Blackout uses the same components as a 5.56 … Continue reading Building a 300 Blackout AR: Why the Bolt Carrier Group Matters