Can't comment on the bore sight, never used one on any of my nagants.

The Mosin Nagant is a tricky one to get the hang of at first... not only are you dealing with a rifle that was mass produced in extreme excess, but could have seen heavy use (or none at all) by the time it lands in your hands.

Some Mosin 91-30's were "battle zeroed" out to 300 meters with bayonets in place, I've been told that removing the bayo can affect accuracy but have not tested this myself.

My M44 on the other hand, was zeroed at 200 yards. This meant that it was extremely hard for me to find paper in the beginning, not knowing that was the case.

The other issue your friend is most-likely dealing with is massive flinch because of the kick that these deliver. He's already said he doesn't like shooting it much, so I wouldn't doubt that he tenses up pretty good by the time the trigger breaks.