I have used on 2 calibers with excellent results. My dad's old Mauser with the original barrel went from 2 1/2 inches to 1 1/2. I broke in a new barrel (it was an 6.5-06 Ackley) so I had to make cases anyway. I used 5 of each. The rifle shoots .6 inch hunting loads. David Tubb is the worlds best shooter and he doesn't sell things that don't work. You must follow the instructions carefully with frequent cleaning during the processbeing essential. Go here and read the info from the horse's mouth. http://www.davidtubb.com/finalfinish.html

Regards, Rick.