hallo

the M 95 is a old war horse and so far as its possible trouble free
I can only imagine that something inside the bolt is worn out or very dirty. if it happen only after shooting and not "dry" the bolt head must be jamming inside the bolt after the bolt head get a serious kick. the bolt head rotate inside the bolt by guide grooves and driving studs and there is where I would look.
do you know how the disassemble the bolt?
here is a video: http://www.youtube.com/watch?v=MvGhoye7asA