SOTAR Secret Shopper - Ruger AR556 - Part 3.5/4 - Had to Lap Three of Seven Upper Receivers
This video details the process of lapping an AR-15 upper receiver face, a critical gunsmithing step to ensure proper barrel alignment. The instructor demonstrates how to identify an out-of-square receiver face and explains the importance of a flat surface for accurate sight and optic zeroing. Three out of seven tested Ruger AR556 upper receivers required this corrective action.












