To put it shortly, my KMP9 is a very accurate, loud, and powerful springer. I need to pull back on the charging handle after every shot if I want to shoot a bb out of the airsoft gun. I found a video on youtube of the exact same problem I am having with my KMP9.
I disassembled the airsoft gun and discovered that around when the hammer reset block comes into contact or surpasses the hammer, that the friction between the bolt and the lower receiver increases dramatically. I believe that this high amount of friction is what prevents the airsoft gun from cycling fully and resetting the hammer. Now I cleaned and lubed the gun and payed special attention to areas where the bolt makes contact with any other surface, but the problem still remains even though everything looks fine to me.
I just want to make it clear that I am comfortable disassembling the KMP9 and would prefer not to send it in to KWA (my M9 PTP has been there for the last two to three weeks and I miss it very much. I would tear up if I had to play multiple games without my KMP9, aka my favorite gun in my airsoft arsenal.)
Now a little info about the gun and the conditions in which it broke...
-I got it in mid-February.
-Originally ran propane, but after breaking two gas cylinder chambers and the breech base, I switched to green gas and have not had any problems until now (made the switch sometime in March.)
-I filed down the sharp edges of the bolt catch so I do not believe this can be the cause of the high friction.
-The gun was well maintained and I had cleaned and lubed it after every game.
-Temperature was in the 90's. The gun barely passed chrono shooting at 398 fps with .20s.
-Gun worked fine until the problem occurred and showed no prior sign of breaking down.
Thanks in advance for any help. I look forward to your responses.
Edited by 2good2betrue77, 26 May 2012 - 08:26 PM.