I’ve used Winchester SRP in my CZ’s ( PO-1 and my PO-7) without problems, one thing to remember, as a rule you should reduce your powder charge about 1 grain, because the rifle primers DO burn for a longer period of time and burn hotter, they have to, as some rifle powders are harder to get lit, than others. At least that’s what I’ve been told. Anyway, reduce your charge at first, and work your way back up.. That’s the rule of thumb I’ve went with, and it’s always worked..