On a related note, though not an AK conversion.
I have seen Carcano rifles converted to use the 7.62x39 cartridge. The 6.5 Carcano has a 'close enough' base and the clips take the x39 just fine. Likewise, a 38 or a 357 fits the bolt face of a Carcano just as nicely as it does the AK bolt.
I have been thinking about getting a .357 Desert Eagle magazine and using it to evaluate the possability of making the Carcano take the mag through the bottom and rebarreling to 357/38
I know, the obvious question is "Why?". Because the 38 special is an easy centerfire round to suppress. Low pressure, easy reloading. Most 9mm cans will do just fine with it, but I'd consult with the maker before putting any round other than what's stamped on the can just as a CYA. 357 could be loade subsonic, or shoot full boat 357 unsuppressed. That way the rifle still has at least some power. Besides, Carcanos aren't exactly big dollar guns. Tearing one apart for experimentation isn't going to break the bank or deprive a collector of his treasured safe queen.
Anyway. I have been tossing this idea around for a while and figured I'd run it by you guys. I won't likely do it anytime soon. I don't have a carcano (though a friend of mine does and has said he'd give it up cheap if I want to try this). I do however have a handi rifle in 357 that's at Tornado Tech getting shortened and threaded, yet another reason I'm in no hurry to do another rifle in the same caliber.