Bought the upper and installed on a 223 lower that I had. Do you have to change the buffer spring or anything else after the conversion? Thanks for any help.
Sometimes you will need a longer firing pin and/or a heavier hammer spring to ignite Eastern Bloc steel case ammo, a D ring added to extractor is good if you happen to have extraction issues.
Did you get the upper on Midway's deal? Wondered how theirs looked.