Nice day today so I went out to the range to shoot the Staccato C. Fired about 40 rounds when the 4th round in the current magazine went boom. Bottom of my hands were black and stinging and my face was stinging. Blew the magazine out of the gun. Scared the begeeba's out of me to say the least. I may have even said a bad word. Checked myself and no damage to me, guess it was hot powder on my hands and face. As I always do, I had eye and ear protection on or I shudder to think about what may have happened to my eyes. Checked the gun over pretty good and all seemed to be well. I then proceeded to shoot 290 more rounds through the gun and everything functioned well (with the exception of my groupings, my hands may have been shaking a bit more than normal). When I got home I started to clean the gun and that's when I found an issue or two. The problem didn't show up until I started to get the gunk off. This was a real eye opener for me as it didn't occur to my tiny little brain while at the range that potential problems could be hidden because the gun was dirty. Rest assured I will not make that mistake again. I think what happened is the round did not quite fully seat, leaving a tiny gap. I'm not too good with describing things so I'll let the following pictures explain.