So I'm starting this review off with the most important thing about this gun.... NOT all BBs are created equal. I struggled over this gun for weeks with very little success. I tried so many solutions in order to to get the magazine to feed properly. Nothing worked. Little did I know, it was not the gun's fault -- it was my fault. Maybe my gun came more sensitive then most, but every brand and weight of BB I have jammed in the magazine. As it turns out, as far as I know, this gun ONLY accepts KWA-brand BBs (I'm sure very similar brands would work too, but I'm not going to guarantee anything). The moral of the story is DO NOT skimp out on BBs if you are interested in this product (or any quality airsoft gun for that matter). (I have heard that KWA is very picky when it comes to BBs and magazines, but this is my only KWA product, so I can not say this from personal experience).
Onwards with the review... This gun product definitely lives up to the KWA reputation. Everything functions smoothly, the gun is built to last, and the internals seem strong. The only complaint I have regarding the build of the gun is the cocking handle; it is made out of a polymer (just like the majority of the gun) but because of it's size and shape, I fear that it could break off of the gun's metal internal bolt. The magazine, however, is extremely durable. It is entirely metal (with the exception of the rubber gas lips and o-rings). It survived a 4-foot high drop onto concrete when I accidentally hit the mag release instead of the firing mode selector.
The KMP9 is not built with a safety, but removing the magazine acts as a safety feature. I believe the original release of this gun did not have a firing mode selector. This problem has apparently been solved, and it now has a semi-auto/full-auto button selector. The folding stock works great and is actually surprisingly strong with minimal wobble when in use. The only issue is that when there is a fore-grip or other accessory on either the side or bottom rails, the stock has a hard time locking in place -- if at all.
Shooting-wise, this thing chronoed (is that spelled right?) for me at approximately 375fps & 20rps with 0.25gram KWA BBs using propane (propane usually adds roughly 20fps).
Overall, I'd recommend this gun for anybody who wants to invest in a couple magazines so they can bullet-hose some guys in a CQB situation. Just make sure you use proper BBs.
Relatively Simple Disassemble
Stock Functions Smoothly
High Rate of Fire & FPS
Gas Blow Back
VERY Selective when it comes to BBs
No Threads (aftermarket threaded barrel is available)
No Real Trademarks
Flimsy Cocking Handle
Pretty Weak Blow Back
Accessories Impair Stock Folding
Rating: [4 of 5 Stars!]