I had a 10" twist Pac-Nor in 30BR. I loaded it with 155gr A-Maxes and Varget, accuracy was good and fun to shoot, but it gave me no advantage over my 308 and had very similar recoil. Brass prep wasn't bad, and I had made a custom set of Lee Collet Dies for mine which made reloading easy. It just didn't give me any advantages over the 308 in that configuration. Had it been like redlabel's with the slower twist I may have had a different opinion.

Why not try a 6BR? Barrel life is good, easy to load for, good brass available, and an 8" twist performs well with all bullet weights available for the 6mm bore. Just a thought if you're building a paper puncher.