I have a CZ 527 in 7.62x39. It is amazingly accurate with .311 Hornadys (150 grain SP's). Hornady lists some loads in its manual. I found that my rifle will handle a bit more "ummpht" than Hornady recommends and since their loads are very low pressure, I feel just fine with what I've done. Your choice, though.

With .308 bullets, I got an inch to a little bigger groups. Every once in a while, I got a 2" flier. With the .311 bullets, you can't make the gun shoot more than .5" and that's at more than 2250 fps. As I said, it is amazingly accurate.

I have a Leupold 1.75x6 scope and find it about right. A 4x compact would be good, too.

As to effectiveness on deer, I've taken only 3 with the rifle, but none did anything more than run 20 yards or so. All were shoot-throughs with little meat damage, but seemed to have good expansion judging from the exit hole.

Pecos45
Several years ago I took two whitetail does with the 30 Russian Short. One shot was @85 yards the other @50. I used Hansen Soft Points. They were very effective.