Rock River Arms BT-3 Completed Upper Receiver 6.5mm Creedmoor 32in 24in Barrel Standard SS Fluted Profile 1-10 Twist 5/8x24 Thread M-LOK Handguard. . These AR15 Upper Receivers through the expert product experts at Rock River Arms are designed using...
Rock River Arms BT-3 Completed Upper Receiver 6.5mm Creedmoor 32in 24in Barrel Standard SS Fluted Profile 1-10 Twist 5/8x24 Thread M-LOK Handguard. . These AR15 Upper Receivers through the expert product experts at Rock River Arms are designed using...