01-21-2020, 02:21 PM
So my long time friend is a machinist/metallurgy and was telling me that lapping an ar15 upper removes the hard coat anodized coating and exposes the soft aluminum which totally reverses the purpose of hca. He said if your going to be lapping it I should do so very sparingly so not to remove all the hca. He measured 2 of my aero uppers and they were almost perfect so I didn't do the lapping but did bed the barrels with locktite 640 and they both shoot lights out. What are your thoughts on this. If we buy quality parts is it necessary to be lapping or not.