Hey Guys I have a question for you. First I went to the range with a few test strings. One loaded with H-1000 and BR2 primers the other loaded with H-1000 with magnum primers. All groups were smaller with the mag primers. I was shooting at 150yrds and the smallest group measured .669. So the question is, is it the primer that you use determined by the caliber you are reloading for (300 Win Mag) or the powder you are using? Like R-22 or H-1000 that are "magnum" powders. For instance if you used h-1000 in a 25-06 would it be wise to try the magnum primer. (the funny part is i also had some H4831 loaded both ways that seemed to shoot better with the BR2's). thanks for your input!