Buy an AK if you want 7.62X39. Rugers will work, but last time I checked, the bore was .308 and not .311 like the wolf and com bloc ammo. Function and accuracy may be impaired by this unless you want to buy the expensive remington ammo.

For this caliber: Buy a Bulgarian AK and feed it from good circle 10 mags.

They are scrambling to get 308s in the sand box. Less likely to stand up once hit (unlike 223).

Whittakers has excellent prices on 308 ar-10s or whatever you decide to get. Ship to your FFL.

http://www.whittakerguns.com/