This is the 6th consecutive time taking this gun out that it has malfuntioned on me this started in the last 1,000 rounds or so, last summer was when I first had an issue, my buddy was shooting the gun and it continued to fail, 4 times through 2 19 round mags. The failures have all happened with Winchester White box (200 rounds), Remington UMC (150) my friend's Dad's reloads (75) and a box of 50 I can't remember right now not Federal Champion, all of them 115gr. which is the reason bullet weight was mentioned in the first place. Usually the gun will malfuntion every mag or 2, yes I keep track of my magazines. Of the other 500 rounds of various ammo all 124gr. no issues, pardon me for thinking the bullet weight may be the issue. As stated before the same ammo ran through my Shield, 1911 9mm and Glock w/o issue, I wasn't, nor have I been shooting the CZ much lately as I was tired of dealing with the issue and had a lot of 115gr. ammo to go through. My local LGS suggested asked me what I was running and said they've found similar situations with the gun and to step up bullet weight, I verified this with another dealer. I've also been shooting my .40, .45 and .357 sig a lot lately, no malfuntions in any gun (even the 1911), so I have a hard time believing this is how I'm handling the firearm while shooting, but thanks. I've asked around and figured I'd ask the forums before getting ahold of the manufacturer.