AR10 Frankenstien Remedied

Received this AR10 incomplete. Used a lower parts kit to put it back together. Lots of discover for me. I did not know AR10s use a tiny screw instead of a roll pin for the bolt catch. This ine was stripped. BTW bolt catches are made from hardened steel. In order to drill through that I had to use a masinary bit. None of my other bits would bite. The firearm had a rifle length buffer in a Carbine length buffer tube. This was a good education.