I took my M9 to the range yesterday, and experienced a series of "failures to fire", and I am seeking some advice. This was my second trip to the range with this gun. The first trip went well with no problems...as reported in my previous thread here. Since the first trip to the range, I followed the cleaning and lubrication advice posted in the maintenance area of the forum, including the thread on slide disassembly. I also bought a second magazine (14 round) to go with the 10 round version that came with the gun. I took a new box of WWB to the range to try out the new mag and see if the cleaning would improve the shell ejection path. The first few rounds went through fine, but the fourth or fifth round simply did not fire. I did not feel the trigger release the firing pin when I pulled the trigger back. The slide seemed to be correctly positioned, and the indicator showed a round was in the chamber. I removed the clip and pulled back the slide to manually remove the round. The round showed no visible imprint or firing pin marks...nothing. I re-inserted the mag and it fired fine for about three rounds before it repeated the problem described above. I tried switching to the 10 round mag, and it repeated the problem after about three or four rounds. I tried switching to PMC ammo in each magazine, but the same problem still occured. I let a buddy try to see if he could get better results, and the problem did not go away. I pulled the slide off to see if there was any visible internal damage, but I could see none. Has anyone ever experienced this issue before, or can anyone offer some advice? Is there something that I could have done during cleaning to cause this?