6.5 prc is a big rifle with 69gr powder capacity? Mid class in my mind. It's the smallest case out there on 537 case head. Essentially a recreation of the 6.5 rem mag minus the belt. I personally tested cci 250, 215m, 210m br2. And 210m had the best accuracy and lower ES/SD vs the other 3.I use fed. Gold mag match primers in all my big rifles. Got lucky and found a few before the shortage.