You'd have to have a mighty small thumb to reach in through the bolt opening :).\n\nDoes the magazine drop easily when the action is out of the stock? If so you do indeed need to remove a bit of material from the side(s) of the magazine well in your stock. On a wooden stock I ve had good luck using a metal scale as a scraper to adjust the magazine well. I've never done this operation on a synthetic stock. The business card as a feeler gauge is a good suggestion.