I agree with the above posters, try some better ammo, I reload, and one of the main reasons for reloading my own 9mm is because I feel I can do a better job of QC/QA.. I hate to say it, but the quality of pistol ammo within the last 10-15 years, had been going downhill rapidly.. It's not unusual to find out of spec rounds in a box of ammo anymore, whereas 10-15 years ago it was kinda rare.. Winchester white box is usually a bit underpowered compared to European 9mm which is close to +p ammo here..But yeah, try better ammo, if that dosen't work, call CZ, they'll take care of you..