My Wolff 18lb spring arrived. The spring was about 3/4's of an inch too long so I cut off it to the length of the original CZ-75 Pre B recoil spring to make it fit. Went out and shot 10 rounds of 124g +P and my reloads. The slide locked back like it was supposed to and the CZ-75 has a nice tighter feel to it now. Everything work's fine now.