My son and I have Mossberg 500 with cantilevered scope mounts. I changed the scope on his barrel this year. When I put the barrel on his gun I tighted up magazine screw so thight it got rid of the gap between magazine and the piece that screw the barrel to the magazine. When I did this it must have caused the barrel to bend because the shot and the bore sight was way off untill I losened the screw. I see the guns in the store all havethe same gaps.

Anyone know how tight to tight this screw. It has detents on it to prevent it from losening.