The Mosin bolt is meant to be fitted. During refurbishment, it often wasn't and this led to hard to impossible bolt operation. What is really a very robust rifle gained a bad reputation in the West for this, and other malfitment, reasons.
The arrows in the photos above point to the areas that often end up contacting almost parallel, and need profiled.
Contour and polish the ramps.
There are notches which, if not cut and polished correctly, may make the bolt harder to close than it needs to be.
The notches should fit into each other shallowly; just enough to retain the bolt in that position but not so much that it requires extra effort to overcome when closing the bolt.Fitting the bolt in this manner, as well as tweaking the extractor, was and is the proper way to fit the bolt and was done on almost all Finnish rifles I've seen since they kept their rifles in service and, if they did refurbish them, took the time to fit the parts.
We see similar issues with triggers on Russian refurbished Mosins; they're not fit correctly, either, and unfitted ejectors prevent easy loading from stripper clips.
The Mosin is an excellent, rugged rifle when a little care is put into it.
Regards,
Josh
