Well you could be experiencing several thing,the majority of the 54r ammo is steel case and lacquer coated. Copper washed steel or even some of the brass case stuff can cause similar problems.
First off steel case ammo doesn't expand like brass case ammo does,when it's fired the case doesn't relax back like brass if you have a tight or dirty chamber it going to be just that much harder to extract.
Second regardless of country of origin you may experience sticky bolt syndrome with either LB or HB ammo in the past when I used to shoot lots of surplus I experiences it with both. Both LB and HB can be high pressure,I've broken down quiet a number of different surplus rds. lowered the powder charge and experienced better accuracy and better extraction along with felt recoil. Handloads in most cases usually take care of the problem all together as long as the rifle is in proper working order.
You might want to give the sticky bolt fix a try and see if it improves things and use a buffer wheel and some fine polishing compound to polish up the bolt lugs,it want hurt to put some of the polishing compound on the lugs themselves and rotate the bolt head to polish the insides. As far as blowing up your rifle with surplus I highly dough that will ever happen the Mosin rifles are way overbuilt,you would have just as good a chance doing so with you own handloads as any surplus,I've seen cases split all the way down the side,blow the primers out and never hurt a thing.