My new CZ SP01 Shadow Custom has been having the occasional fail to fire. It has happened only on the first round loaded from a magazine, and almost all of those from when I used the slide release to load a round rather than when I pulled and released the slide manually. It happened today three times with some American Eagle ammo, but it operated flawlessly with a box of Blazer. My Shadow Custom has a light trigger - a bit over 3.5lbs, so I know that could be a general issue. Any thoughts about this? I'm not sure of the cause, when I look at the round that failed, I can't see an indent at all on the primer. Also, do you know of a list out there that tells you which ammo has harder or softer primers? I love the pistol and it's really more of a range gun than a protection gun, on the other hand I'd like it to be reliable for either.