Tried an AICS pattern magazine. Length should be OK, width at the front is too great. Might be possible to adapt the trigger guard and magazine well.
---------- Post added at 04:55 PM ---------- Previous post was at 04:51 PM ----------
Shouldn't need a barrel liner - just a long chamber insert. Or the breech of the barrel cut off and made into a sleeve, with the barrel set back into it, and a new chamber cut.