Tanio Koba / KJW M4 GBBR Basic Information and FAQ

[Thenooblord]

well I put the sear back in and it seems to be working now, dunno why but I can't complain

[LocoYokoPoco]

So, after some pretty good jimmy riggin, I managed to get an aftermarket WE Charging handle to work.

[SKI]

Originally Posted by Thenooblord

Thank you for your incredibly helpful and constructive comment, remind me to tell you to go fuck yourself if I should meet you in person, along with some BB Bukakke in the groin.

Anyways, I'm suspecting the issue is related to the sear mechanism being tripped by something other than the bolt carrier (vibrations, body flex, etc) so the hammer falls early and doesnt hit the knocker squarely, because when it starts messing up it fires weakly like the hammer isn't hitting hard enough, possibly riding forward on the bolt carrier, I can be sure by removing the FA sear altogether and see if it misfires the same, then it would atleast help identify the issue.

Dude! You have met me and played along side me under my command. I also let you try out my KJW at the Twat field that same day. You couldn't stop jizzing over it. I have heard countless stories of your shit not working after you fucked with it. I am all for people who like to tinker and gain knowledge about their equipment but most stories I hear of you and from you are the result of you not knowing what you're doing. I guess you can't learn if you don't try but some professional guidance might be in order.....And don't ever speak to me like that again.

[audi_bhoy]

Is there some separated lower bodies available somewhere? A friend of mine has his pistol grip spot messed up, and of course it is a plastic one... PM would be appreciated

[baker_Jeff]

Originally Posted by audi_bhoy

Is there some separated lower bodies available somewhere? A friend of mine has his pistol grip spot messed up, and of course it is a plastic one... PM would be appreciated

Checking for you

[audi_bhoy]

Thanks!

[LocoYokoPoco]

Originally Posted by LocoYokoPoco

I'm having a few issues with mine Semi auto doesn't cycle properly (trigger doesn't reset after each shot), and the charging handle "blows back" when firing as well :/

For the record, if anyone is having the charging handle problem I had, I fixed it. I noticed that the cap on the end of the buffer tube was loose to a good extent, so I applied some loctite on it and screwed it back in really tightly. It worked like a charm. Too bad I had to go through 3 charging handles to figure that one out. :banghead:

Also the trigger problem was fixed by replacing the selector switch and reassembling the entire trigger assembly.

[grantmac]

Having a little issue with my CQBR and wondering if anyone has had a similar problem.

Its suffering cooldown quite noticeably, much more then when new.
In the final stages just the rear of the bolt will cycle without the front moving.

I'm running the cradle piston and velocity reducer.

Thanks,
Grant

[andrew321]

I had the exact same thing. T-hum ( creator of the cradle parts), made me aware of the ice that builds up during full auto shooting. It causes exactly what you say, jamming up the piston. Apparently they use a new "x-ring" that helps this, but im still waiting over two months for mine .... In the meantime, ask Amos about the RA tech upgrades... He seems to think they might show some promise.

[Amos]

Yea still working on getting them.. RA-tech hasn't answered my recent emails yet

What type of lube are you using on the o-ring? An oil will thicken up, but a good grease will stay just as viscus.

[grantmac]

Well I've been using a white lithium grease but I think I need something more of a petroleum jelly sort of consistency. Any suggestions would be great.

I have the X-ring on my piston.

The one thing I've noticed is there is not a very close fit between the piston and the cylinder wall. You'd think the blow-back would function much better with a decent seal.

Also the top seal (part # M15) on my mags are showing wear from the bolt-carrier sliding across them. Could it be my carrier has some extra casting flash or is out of tolerance?

Cheers,
Grant

[Amos]

You shouldn't use white litium for sealing parts, after a while it gums up and does the opposite of what a lubricant should.

I'd suggest using a 100% pure silicon grease (ARS Sticky-G Silicon is what I use on all the GBB's)

If you find it's too thick you can put drop of silicon oil in and mix it around to cut it down.

[audi_bhoy]

Anyone has a clue on how to take the hop-up unit and rubber out? Can't figure it out right now!

[grantmac]

Anything of a more commercial nature that would work? Same lube for the mag-top seals?

Also any suggestions for metal to metal parts? I'm thinking moly for that.

[Castle]

Originally Posted by grantmac

Anything of a more commercial nature that would work? Same lube for the mag-top seals?

Also any suggestions for metal to metal parts? I'm thinking moly for that.

I'm currently using Permatex Ultra Slick Extreme Sport synthetic grease on mine. It can be found at CT.

(If that's a bad idea, someone please correct me!)