PSA JAKL,8.5" 300BO NATO Nitride, With BCG, Bolt Catch and Bolt Catch roll Pin, Smoke

PWS AR-15 MK109 MOD 1-M Complete Upper Receiver 300 Blackout 9.75" Barrel Long Stroke Piston

Maxim Defense PDX AR-15 Complete Upper Receiver 300 AAC Blackout 5.5" Barrel Arid

Daniel Defense DDM4 300 S AR-15 Pistol Complete Upper Receiver 300 AAC Blackout 10.3" Barrel

AR-STONER AR-15 Pistol Complete Upper Receiver 300 Blackout 10" Barrel

POF-USA AR-15 Renegade+ Complete Upper Receiver 300 AAC Blackout 10.5" Barrel Carbine Length 9" M-LOK Handguard Black

Radian Model 1 AR-15 Pistol Complete Upper Receiver 300 AAC Blackout 8.7" Barrel

CMMG Resolute MK4 Upper .300 AAC Blackout 16.1 Barrel No BCG/Charging Handle