Mine is also a CZ 527, the 221 will make very good velocities with a 22" barrel. Mine shoots 40's and 52's equally well. But the 40's run just shy of 3500 fps, Rl7,aa1860,Lil gun and CFE Black all shoot well. But CFE black gives me the best combination of accuracy and speed. Awesome caliber, one of my absolute favorites for varmint hunting.
