Smaller case volume of .308 requires full grain charge reduction from '06!
.30-30 data is good for starting cat sneeze loads in .308. Reduce the .30-30 data a full grain for 7.62x39.
DO NOT enlarge flash holes. Doing so is Unnecessary and is unsafe if you inadvertently mix up cases and put a full charge in.
With the fast-burning pistol and shotgun powders no filler is necessary or recommended. Doing so raises pressure and you can ring the chamber neck of an '06 in doing so, which I have done...