i have a federal 9x19 barrel in my cz52, the only prob i had was this:the chamber is a tite one so when using reloads use fresh unshot brass and then full length resize it,other than that it eats all factory loads no probs no sweat,and on the cz52 of mine the headspace was correct being a drop in fit.no sqwauk here for a korean/chinese barrel(cant remember where made, i had 5 kids freaking out in the house when i talked to lady at fed arms) and it holds tite groups as well,maybe i lukked out? any other feedback out theyre?