It is quite a daunting task...I have done it....on a 50 no less.
It was a BBQed barreled receiver, with an unpainted (until US owner) bolt carrier...which was chipping, which made me start stripping. Carrier was some kind of semi heavy duty rattle can stuff, the rest of the gun was pure Russian BBQ.
You have no idea what may be under the paint. In the parts I used to restore mine, I found more than a couple different ways the metal was prepped for the paint. It is a long way down past the paint until you get to unfettered metal.