I've seen the californian AR15 .223 varriants that use a fixed 10 round magazine, which got me to thinking... Even though I don't live in cali, I'd like to have an AR lower that takes AK magazines, even if they were fixed in place. AR47.com is down, but even when it was up, they wanted 350$ for an AR lower that could only ever fire 7.62x39mm, so its not really modular, and it's another 75$ to mill out the bolt carrier to work properly. I think the real stumbling block is having the mags lock into place and feed. If there was an AR lower that accepted a fixed AK47 magazine, it could be done a lot cheaper I would guess. Do you think it would be possible to cut into a standard AR lower magazine well and fix an AK magazine in place with a few set screws? I found this video on you tube: California AR47 ... metroshot but i have yet to track one down.

Not sure why you'd care what mag it takes if it's a fixed one. I'm sure a 10rd fixed lower could be done for an X39 upper.

Since I don't live in Cali, I can have any cap mag if I want; so long as it's preban and still work in the rifle it was originaly configured for.

I've seen AR-47s which take AK mags at the fun shows. They have lower receivers made to take the AK mags and shoot 7.63x39 rounds. It's less expensive to buy two AKs (one Romy and one Yugo) at the price of these AR-47s or four (Yugo) SKS rifles.