Been trying to figure out why I need to slap the bolt of my new M39 with a lot of force to open it when the firing pin is forward/after firing a round. Google says it's called "sticky bolt", and there are tons of causes, from caked on cosmoline to burrs and rough machining on the bolt and in the chamber.

Well I've cleaned everything and my chamber looks fine, but the bolt has a lot of wear and some pitting on it. I've been polishing up the spots where the bolt parts cam on each other when I got to these two chipped/worn surfaces.

What the fuck? This is the cause of my sticky bolt right? Should I just sand them down or what? I don't want to fuck my bolt up.

Can someone post a pic of their bolt pieces so I can confirm that mine isn't supposed to look at fucked up like this?