I think a 7.62x39 would be fine, it just depends on what gun you get, the CZ edguello was talking about is a bolt-action, if you get a Ruger Mini-30, it should work fine for you.

One thing you need to realize is that 7.62x39 ammo is MUCH easier to find than .223, because lots of .223 is being sent to Iraq for the M16.

The 7.62x39 isn't a bad cartridge, it's just that cma can be full of crap at some times.(j/k)