KJW M9 IA-FM, gas efficiency and firing issues.
 

So I have a KJW M9 and it has been nothing but problems.

First I have no idea whats going on in a gas pistol so that helps. With both my co2 mag and my GG mag I can only get 3-7 shots off before the gun makes a half cycle and dumps all gas. For the co2 im doing nothing but putting my cartridge in, tightening down till I hear nothing, and firing about 1 round every 5 seconds.


For the GG mag Im pushing my valve in, put the GG can on, dump through the mag to push out all air, close valve with GG can stil on and pouring, fill mag for 15-30 seconds. I then leave it for 20 minutes in a 20c+ environment before I fire 1 round every 5 seconds.

Now just starting today after every round the cylinder assembly gets stuck between the barrel and the slide.

Does anyone know whats going on? In the 6 years I've been gone did KJW take a nosedive in quality, or did I just get unlucky?

Sounds like it either needs to be lubed (under the nozzle on the rubber seal) or your nozzle is cracked/broken.

Well I lubed and cleaned it but still have all my gas vent after 1-5 shots so nozzle must be broken. Great haven't even gamed the bloody thing yet.

It's a common problem with the kjw pistols.

The slide is too heavy and the red nozzles are really bad quality. Try to swap it out with an aftermarket piston if you can. If it's a blue nozzle it can still be the culprit.

To test for a nozzle crack, remove the blowback unit (the housing under the rear sight, and put the nozzle in the piston. With your thumb on the square opening if the nozzle and your index finger holding the loading nub, blow into the hole at the front of the nozzle. You should notice considerable resistance but not total blockage when blowing in. If you can move the bbu back out of the nozzle there is good compression otherwise if the air just flows out you may need to replace the mentioned parts.

well i did your nozzle test and sent my ?piston? in to my monitor so i think thats fine. gonna try sanding the rails a little see if that helps. maybe there's a little too much paint and the extra resistance is causing my gas efficiency to drop.

It's more likely that the slide is too heavy and the recoil spring is too strong. Try swapping it out or use a different slide if you have one. It doesn't matter how good the seal is if it requires the whole mag to cycle the gun.

We never did figure out why my friends kjw 1911 had the same problem but it's a common problem among kjw's.

I have a similar problem with my KJW P226, but it was heavily modded by a previous owner.

With standard KJW magazines, it will fire 6-8 shots then fail to cycle or vent gas as you describe.

With TM magazines, it will fire 12-14 shots quite well, but no more than that. My "work-around" is that I only run the TM mags, and I only load 12-13 bbs in the mag.

A friend suggested, like Rainy Eyes above, that the recoil spring may be too strong for the application and to try a less strong spring. I do get much higher FPS with my P226 than my other pistols, so I imagine that has to do with the spring and other modifications that the previous owner made.

I think I may invest in a pistol recoil spring that's a little lighter and see what a difference that might make.

necro


i found that locktighting and really torquing down the slide rail screw fixed both my gas and nozzle issues, at least with c02. my niagara package should be here monday so i can test with propane then.

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