And here we are stripped down and ready to be boiled. There's no need to degrease anything. This poor guy is as dry as it gets.
The frame can be saved, but I'm pretty sure that there will be some horrible pitting under that mound of rust on the cylinder.
There are good and bad things about replacing the cylinder. The good is that this gun is new enough that the cylinder is not serial numbered. The bad is that the gas ring is on the yoke and I only have two spare cylinders in that configuration. If for some reason I can't make one of those work then I'll be into a yoke replacement also.
To pass the time while the water came to a boil, I searched through the pile of spare yokes….and it really is a pile.
I think it's just a big gap. A yoke alignment tool drops perfectly into the hole in the recoil shield. If I had a pointed range rod I would try it….
The first boil and card improved things quite a bit. It still has freckles, and most of them are going to have pits underneath. The cylinder still has big mounds of rust that are dry inside. Gentle tapping with a small hammer produced a pile of dust.
Replace the cylinder..to remove the pits you have 2 options...build up the surface(welding) OR grind down to the base...either way your weaking that particular chamber....Just my opinion
One could turn the cylinder to a smaller diameter on the lathe. There is plenty of meat for that, but the easier solution might be a different cylinder, since there are many close at hand.