You will probably have to work a little on the right-side guide. This must be done slowly and carefully. Take the receiver out of the action and put the floorplate back on. Make up some dummy rounds. Then, using the dummies, look to see where the round is hanging up. It may help to use lipstick on a couple of rounds and see where they contact the guide rib. Since the shoulder of that round is farther forward than the shoulder of the original round, the point of attack will problably be at the rear of the guide part of the rail. Using a Dremel tool and a round grinder, trim away a little, and try it. If nothing changes, do some more looking. I can't tell you from here where or how much to cut. If you don't want to take a chance of hurting the receiver, take it to a gunsmith.