Unfortunately, they discontinued 7.62x39mm because of misfires with Soviet-bloc milsurp ammo. That ammo is made with very hard primers to avoid slam-fires in Rooskie and Chicom firearms, which usually don't have firing-pin return springs. A normal American hammer spring sometimes isn't strong enough to dent the darn stuff deep enough to set it off.
The reverse is also true -- a Chicom military rifle will slam-fire with normal ammo reloaded with normal American primers. It's a serious safety issue with milsurp rifles, but just a frustration issue with Handi rifles. I wanted a 7.62 in order to use the brass and dies I have for my SKS -- I quit shooting handloads in it after experiencing a slam-fire at the range.
Get yourself a .308 Win, .30-'06 or .30-30 Handi -- it'll do anything the 7.62x39 will do, and do it better, with normal-diameter bullets and reliable ignition.
Dave