Any of the 2 part epoxy resin glues would work fine... I would suggest 90 minute cure stuff.. gives you a chance to mix up a batch, and do it all at once, then use clamps to hold the pieces together. Walk away for day and you'll have a solid piece to work with. Sand.. with a 80 grit or so, it gives a rough surface to bite into. Divots not so much. It'd be strong enough to machine.. deal with much more recoil as well. Its overkill for a .22 honestly.
Loctite makes several versions available just about anywhere..