FWIW, you could look things over and see if it might be possible to adapt a different rifle mag to fit & function, via a purpose-built adapter. A few years back, I was looking at a Remington 710 chambered in .243 at a local gun shop. It had no mag, and replacement mags were pricey, so they had it priced dirt cheap (less than you might pay for a used .22). I had some surplus SMAW 9x51mm mags on the shelf, so I looked at fabricating an adapter for the 710 magwell, to allow use of the SMAW mags. It looked pretty feasible (also had an Uzi mag catch that looked like it would fit the SMAW mags), so I drove into town to buy the rifle - and somebody else had already bought it.
Might also look at converting it to a traditional fixed mag, that loads through the action (I've got a Savage 110 stock that's been fitted with a cut-down, fixed BAR mag). As my friend Captain Obvious likes to say, "It all depends on how much you like to tinker, and whether 'looks' are a priority!"
Once again IMHO, FWIW, YMMV, is-it-just-a-tool-or-something-else, etc.