I have a Ruger Hawkeye in 7.62X39.
I shoot .308 150gr. hornady flat based spire points. "interlock" I believe.
They shoot great!
I normally get 1.25" or better groups at 100.
With cast boolits, I am shooting the Lyman 311291 (170gr) round Nose,gas checked bullet.
Sized to .310".
Lyman moly lube
So far I have tried a harder alloy (11-12BNH).
I have tried trailboss, IMR SR4759.
The IMR SR4759 shoots into 1.5" or less at 100yds consistantly.
If my memory serves me correctly, I think my velocities were in the 1650-1750fps range.
I seated my bullets so that I had very "slight" ingraving into the rifling as I closed the bolt.
If you try shooting cast boolets, donot forget to just slightly bell the case mouth so that the bullet doesnt get damaged (shave lead off the side of a missaligned bullet)when seating th bullet.
If you are shooting a SKS, you might want to size the bullets to .311-.312 for cast boolit shooting.
I hope this was what you were looking for.
Good luck and have fun!