I just received a mossberg m44us that the CMP is selling that has a bad flat spot in the muzzle. I'm going to rent a muzzle crowning tool and recrown this m44us plus a couple more old .22 barrels. While look at Reamer Rentals site I got the idea to rechamber this m44us in .22 WMR. The m44us has a good bit of metal around the chamber so I believe it could handle the higher pressure. Rechambering and a little bolt work should be all I need to do to make a single shot .22 WMR. Is this do able? Sounds like a good project to learn a little about metal working.