Decided to change the gas tube on my first/oldest AR for reasons. Had to remove the Centurion C4 rail, which I installed 6-7 years ago. Rounded off the smaller front screws, both of them. An extractor hex key hammered into the first one worked like a charm. Not so on the other one. Had to dremel a slot for a flathead. Prettttty sure that's red loctite in there. Well, that was dumb of whoever installed the rail. Going to bump the buffer up to an H2 and replace the action spring with a Sprinco blue as well (6920) as part of the makeover