I know what you mean about the 6BR being about the perfect 6mm for varminting. I'm shooting 32.0 grains of VV135 and 70 grain Sierra Blitzking in my 6BR with a Pac-Nor #5 with a 1-12"twist 3 groove. It was actually the first bullet and powder I tried and I am shooting groups out to 400 yards between 1.75 and 2". I love the accuracy, but I do hate that fact I had to make it into a single shot. I tried the Bryant conversion and I could never get it to feed right. It's funny you mention the old 'paper box stuff' because I am using it as well. I hope I can get the kind of mileage you are getting from your barrel.
