My favorite load for my CZ is 28.0gr Benchmark under a 50gr VMax. This load gives me a consistent 3500fps, and good accuracy.

All my AI brass is fireformed once (at least) fired brass, nary an issue. I like to use Winchester Nickel for my hunting loads, just because its easier to find in the grass. I am seeing good life with them, with the occasional split neck after the fourth or fifth neck sizing.