If anyone is having failure to fire problems. What I believe you need to do is look at your fired or unfired cartridge. If the firing pin is not striking in the center of the primer, if it is hitting of to the side you have a slide issue. The firing pin channel has been drilled incorrectly. You need a new slide. I went through this problem. After replaceing my slide i have fired 400 trouble free founds. All different brands of ammo. Call mike at keltec. You will have to send your slide in first and he will send you a new slide. 8 day turn around and the gun is awesome.