I must have gotten a bad batch of CCI 250 primers as most of them misfired. Switched to Federal 215's and no problems. I have never tried regular large rifle primers but will give them a try. KY221 you just can't argue with those results.
Be worth a shot. Ingwe assured me that in the climates that I hunt in; a standard large rifle primer would be fine.
You mentioned misfires, I just got this one back from Ruger because it was misfiring. Headspace checked out ok, but they said it was suffering from light primer strikes. They replaced the breech block, hammer strut and spring, and the firing pin/spring. I have the parts list, I'm trying to remember off the top of my head. It's been fine since then. If the misfires continue; it might be worth checking out
