I agree with Beemanbeme, and Roper. I uniform the necks on my varmint calibers and saw about a 1/10" improvement. But that was in rifles that already were shooting under 0.6" groups. For the average hunting rifle experimenting with bullet seating depth will make a bigger difference, than neck turning. Uniform neck tension does help, but only in a properly tuned rifle. If you haven't done the other little tweeks(bedding,seating depth, primers, etc.) neck turning could easily get lost in another problem that has nothing to do with neck tension.