Wheeler Engineering 661120567578 Delta Series AR 15 Receiver Lapping Tool

Lapping a receiver ensures a perfectly square and true surface for the barrel to mate against, thus enhancing accuracy. Lapping a receiver ensures a perfectly square and true surface for the barrel to mate against, thus enhancing accuracy. AR-15 Upper receiver/barrel alignment is critical to accuracy. Also, honing the surface can produce optimal positioning of barrel nut so ideal torque can be achieved along with proper gas tube hole alignment.