Published specs call for a COL of 2.20. I have been loading to 2.150. The Ruger twist for the 762x39 is 1:9.5. Right hand twist. All this info is readily available with a casual search,
I have never been a Ruger fan but had a chance to pick up a compact in 7mm08 and was to slow on the trigger, it was a real nice gun I still think about it, maybe I should try an American ??