I have the CZ 527 and an AR with a Colt upper, both in X39. I have tried 6-8 different bullets in both and have yet to find one that didn't perform adequately. They range from the Hornady 123 gr SP p to 150 gr FMJ for plinking. Both .308 and 310 were included and I couldn't really see much difference in accuracy. The loads settled on for each rifle stay around 1.25 MOA and often better. I also have a cast bullet load for the CZ that shoots under 2MOA.
So far, I haven't been lucky enough to have an opportunity at a whitetail while carrying one of these, but feel pretty confidant either will do the job when that time comes.
