Hi Ray, for a long time most guys in Campbell River have shot their 6ppc's out to 500yds. We start with a relay at 100yds then jump out to 500 for 3 relays or so then back to 300yds and finish back at 100. The 6ppc's will shoot 2" - 2.5" groups at 500 fairly easily. Lately a few guys use another 6br custom gun for the 500 and maybe the 300 depending on the wind, leaving their 6ppc for the short range. The 6br's with 105's will group around and under 1.5".
One fellow has a switch bbl Panda and goes back and forth from ppc to 6br then back to ppc.
Not saying any one way is better than the other, just how some do it out here.
cheers
Greg