To cure most sticky bolt issues on the average Russian M91/30, repeat after me:
Finnish M39's are in a class that defies their Mosin heritage. GM, I love that M28/76 but you're right, it sure doesn't look promising for a TKIV 85
This sticky bolt issue
, really gets old..it's very simple, If'en you need a hammer or 2x4 to open your bolt after firing
, learn how to clean your chamber better.
I will say this, none of mine have ever suffered sticky bolt, whether or not it's a rare Finnish or a common run of the mill refurb. This is how I learned to do it and it's a very easy procedure....
Take a 20 gauge shotgun bore brush, brass bristle preferred, wrap it lightly with oooo size steel wool, you can coat that with JB bore paste or a cleaner of your choice, mount this on a cheap section of shotgun cleaning rod, chuck the rod in a power drill and then drill it slowly and slightly back and forth in the chamber for about a minute or two? If it's a real difficult case, reapply your choice of cleaner, and hit it again. Now don't go hog wild and try to shove it up in to the rifling, but hey, it's yours.. Then, just clean the rifle as normal. This should remove any and all traces of any casing lacquer, burnt, stuck on powder residue from split cases and or burrs that may be present. 9 times out of 10, you could also be rewarded with a smoother operating bolt as well.
My many Mosins have eaten many nations ammo, from Albania, Czech, Russian, Romanian to Hungary and Bulgarian, light ball and heavy, to even the boutique bla bla non-corrosive retail stuff, and I have yet to experience sticky bolt using the above procedure above once and a while.