Re: 22LR to 22M
i no sure, but contact nef. i think you can send them your action, and just buy another bbl, 22mag, and they fit it for you. All rimfires of a certain model number can do this. Also they make their centerfires to do the same thing. but they all have to be of a certain action/receiver model. also , you can ask them to lighten the trigger, they will do it for free.