![AR Receiver post lapping - clean, shiny, and flat](https://proeliatorllc.com/wp-content/uploads/2022/06/Services_Lapping-760x428.jpg)
Upper receiver/barrel alignment is critical for accuracy! Lapping the receiver ensures a perfectly square and true surface for the barrel to mate against.
Upper receiver/barrel alignment is critical for accuracy! Lapping the receiver ensures a perfectly square and true surface for the barrel to mate against.