Finishing an 80% AR Lower Receiver – Part 3, by 2A Advocate
(Continued from Part 2. This concludes the article.) Results I think my lower receivers turned out great (Photos 15, 16, 17 & 18). The machined edges are straight and sharp. The trigger pocket walls are smooth, almost mirror-like. There are slight tool marks from the end mill, but no touch up or sanding was done until after these photos were taken. Then I touched up the side holes and the opening for the trigger slot with some Aluminum Black by Birchwood Casey. It’s quick and hides the raw aluminum edge. I didn’t treat the entire inside of the trigger …