This is a turnbolt in .17hmr. The mag is a tad loosey-goosey up and down wise; approx. 1/8th" of play, and as a result, it jams low when cycling a new round in, more often than not. So I have to hold the mag up tight with my left hand when cycling the bolt with my right; then it feeds perfectly. So I can see the solution is to pull it up tight. How can I accomplish this? Thanks.