Tanio Koba / KJW M4 GBBR Basic Information and FAQ

[Hazer]

Originally Posted by StanB.

Hmmm, I lubed up the Oring from my piston and the oring from my velocity reducer, put silicone spray on alle moving parts and now the fps values are not that unstable anymore, they now are between 400 and 420 which is kinda steady for a gas gun out of experience.

I already got the screw for the TDC mod and will do it in the next few days.

My new problem is the following: I just got my new hopup chamber and hopup rubber from ratech, adjusted everything properly, set the hupup rubber perfect in place and reassembled everything, but now the bullets just keep rolling out of the barrel, not every shot, but every second shot, disassembled the whole gun again, checked the hopup unit and every freaking thing, messed around with the hopup rubber a bit and reassembled everything, went fine for 3 mags then bullets started to roll out again.

Any ideas WHAT THE HELL the problem could be? Bullets come out of the mag properly, hopup rubber sits perfectly, and is not too thin so bullets get through rather easy and the hopup isn't working anywas so that can't be a problem.

Kinda desperate atm as a game is comming up and I want to go there with my main again.

What size Grub screw did you use? How'd you know exactly where and how to drill? Did you do the mod yourself? I want to do it too, but want to make sure I make no mistakes. Thanks.

[StanB.]

Originally Posted by dotty3107

I have a question about inner barrel. What type (and what length) of tight bore 6.03mm inner barrel can be fitted with this gun? Any recommendation would be helpful.

EDIT: And some information about R.I.S. fitting would be helpful too. Thanks.

I personally am using a 6.03 367(i think) mm tightbore from cradle arisoft, they might be expensive but they work.

For RIS I'm using a Madbull airsoft Daniel Defense clone (16"), but you can fit an original daniel defense and any other ris rails on it.

[ferval100]

Originally Posted by baker_Jeff

Correct, you either have to file the teeth on the delta ring, or file a groove into the rail. If you stare at the pieces long enough, you'll know what I mean.

Is it possible for some pics? Sort of new to modding and don't wanna ruin my rails.

[SKI]

Is there a different website for Cradle Airsoft that I'm missing? the one I go to only have the velocity reducer and o-ring piston.

[D2D]

Thanks radge and beanie. I managed to fix everything by simply shimming the upper receiver and dust cover with electrical tape and heavily oiling everything. The bolt carrier is now well centered without too much friction, the dust cover opens during charging and the bolt catch works properly. I also ground the bolt catch 'tab' on the carrier down a bit because it was smashed and worn down inward to like a 45° angle. Hopefully the electrical tape holds up - I don't want it to be any more permanent than tape, since I'm hoping t_hum's bolt carrier will work without needing shims.

It's just too bad only you two responded to my question. I mean come on, no one else took the 30 seconds to check? Sigh...

[Saberwing]

Originally Posted by D2D

Thanks radge and beanie. I managed to fix everything by simply shimming the upper receiver and dust cover with electrical tape and heavily oiling everything. The bolt carrier is now well centered without too much friction, the dust cover opens during charging and the bolt catch works properly. I also ground the bolt catch 'tab' on the carrier down a bit because it was smashed and worn down inward to like a 45° angle. Hopefully the electrical tape holds up - I don't want it to be any more permanent than tape, since I'm hoping t_hum's bolt carrier will work without needing shims.

It's just too bad only you two responded to my question. I mean come on, no one else took the 30 seconds to check? Sigh...

Mine has similar play to yours, I just keep it heavily oiled though and it seems to be performing fine. Been busy with a VSR-10 project gun I just got to really keep up with this thread lately.

[SixthFall]

Hey guys, I just installed the vr 2 bolt, and the cradle VR and i noticed that compared with the vr 1 bolt, I am getting less fps with the CVR on the vr 2 bolt compared to the vr 1 bolt. What's going on?? I don't have a chrono, so if someone could tell me a good combination of spacers on the CVR to get around 390-400 fps I would be very thankful. Also, what is all this talk about having to trim the nozzle on the vr 2 bolt? Could someone post some pics and/or instructions?

[audi_bhoy]

Been discussed in earlier posts, the V2 bolts requires a smaller O-Ring to work properly. You have to use the stock V2 valve's O-Ring on the CVR to have it working properly.

[SixthFall]

Ahhh, thanks a bunch!

[Saberwing]

Ordering my third lower receiver... I missed Ken's sale of the metal ones so I'm going with plastic as mine has completely cracked below the buffer tube and I want to play. Anybody else gone through a lower or two?

[Gester24]

Hey guys, i have a slight problem, i dont know if this is normal or not, but i have a slight barrel wobble on my kjw m4. it justmoves a bit up and down. could it be the delta ring being lose? if so, does anyone have instructions on how to tighten it? ive searched for youtube videos and it doesnt really make sense as to what is happening. also i read it could be the joint that is linking the barrel and the chamber? if anyone has info that would be great thanks. Oh and does anyone know what RIS i can use without buying from kj works since their rails are 68 bucks a piece, a bit to hefty. Not a free floating one i like my front sight. Thanks.

[audi_bhoy]

I just installed a Larue style free float on mine, fits just well. Beside that the Larue itself is lose and had to be shimmed... All you need to tighten your delta ring is a delta ring tool, the one with half a circle and plenty of round nipples.

[SixthFall]

Originally Posted by audi_bhoy

Been discussed in earlier posts, the V2 bolts requires a smaller O-Ring to work properly. You have to use the stock V2 valve's O-Ring on the CVR to have it working properly.

did this, lubed it up, used my gun in a game, and the o ring has dissapeared? anyone know what happened, like there are no bits of o ring in the gun, and it's not stuck in the nozzle?? Could I find a new one in say a hardware store?

[audi_bhoy]

It was maybe a little loose, and passed through the barrel...

[SixthFall]

kind of what i thought, guess im lucky it's not stuck in there. just seems kind of odd