Tanio Koba / KJW M4 GBBR Basic Information and FAQ

[andrew321]

I agree, internals are more important...luckily though, it seems we can shoot between 350 and 450 as needed, and have an extremly reliable internal setup. Until they come out with some nice after market parts atleast.


And redwolf and ehobby have the mags for 38$ each, and i've found a couple US dealers for 40-45$. Most are out of stock, so we'll see if they ever refill that supply...

[Vieler]

So.... does the buffer toube come off, i wanna put on a single point sling mount on.

thanks

[andrew321]

So I took whats left of the original gun out to run some rounds through this weekend. Put probably 1000 rounds through in one day (alot when mags are 32, and you have to use the bloody loader..).

Verdict on the edgi 6.01 363mm TBB is 100% thumbs up. I personally have never shot an airsoft M4 with that sort of accuracy, consistancy, and range. That being said, for 90$, there may be better "bang for your buck" barrels coming up (I know Cansoft is looking into making some). Will give some proper accuracy:distance specs when I get access to the warehouse next.


The TAF buffer tube extension was simple, and did what it had to do. My WA fixed stock needed some modification to fit on, but was worth it. That being said, my lower reciever is cracked at the plastic on top of the buffer tube..some epoxy is holding up ,but a metal lower would be much needed...


The O-Ring piston head is a definite necessity. When going to replace the original, (only around 500 shots through) the plastic seal was shaved down on the top. For 30$, and 10 minutes work, seems like a no-brainer.


Still working on the velocity reducer. Will update.


After about 700 rounds, the trigger became solid and wouldnt pull. Popped the rear pin, and for some reason the trigger assembly was stuck, but when you went to safe, it reset. After going through a few times, it worked as normal, and shot for another 300~ rounds with no more issue.

Overall, after the upgrades, i'm massivley impressed for what I thought was never going to be a fieldable gun. I'm waiting for 9 more mags, and I think i'm going to try to field it for the mid temp games this summer.

..Now if only my KJW MEU wasnt such a piece of shit...

[baker_Jeff]

So it turns out that the crack is causing more problems than it should. I thought I should test fire to see if anything else is wrong with the unit. It turns out that it will not recock all the time. So on full auto, it will not recock after the shot, and I have to cock it back again even with a full mag of gas and BB's.

Hey guys,

I sold one of these to a customer, and when he received it the receiver was cracked near the buffer tube.

He is getting a replacement lower receiver, but can anyone comment if this could be the source of these other issues with the gun?

I don't want to send him just the receiver and not end up with a working gun...

Thanks for any help!

Jeff

[andrew321]

Mine was split right in half at the top of the "O" on the lower receiver that goes over the buffer tube. Cause no issues for me... but I epoxied and clamped, just to keep it together.

That was my case. Is he gassing it up properly? I don't want to sounds like I know more then I do, but mine had the same "issue" when i got it, and I was just not gassing up properly...

[Rookie Ab]

Originally Posted by andrew321

Mine was split right in half at the top of the "O" on the lower receiver that goes over the buffer tube. Cause no issues for me... but I epoxied and clamped, just to keep it together.

That was my case. Is he gassing it up properly? I don't want to sounds like I know more then I do, but mine had the same "issue" when i got it, and I was just not gassing up properly...

I'm with andrew on that one,and he might want to make sure the piston cup is lubed,silicone grease is what they recommend on Arnie's.

Plus the gun is new and tight, and it will take a couple of mags just to get everything seated right. At least my two were like that.

[sushi_boy604]

Thanks for the help guys. It might help if I added that once I fired a couple of times, it came to the point where I tried to cock the gun but the cocking handle did not retract all the way back to its normal position. It was jammed. Bolt catch was down too so something was definitely jammed in the cocking tube.

As for the receiver, does anyone know if its easy to install the internals? My fear is once I get my replacement, I am afraid that I won't be able to put everything back.

[Amos]

Anyone know where I can get a replacement valve knocker spring?

[SKI]

Originally Posted by sushi_boy604

Thanks for the help guys. It might help if I added that once I fired a couple of times, it came to the point where I tried to cock the gun but the cocking handle did not retract all the way back to its normal position. It was jammed. Bolt catch was down too so something was definitely jammed in the cocking tube.

As for the receiver, does anyone know if its easy to install the internals? My fear is once I get my replacement, I am afraid that I won't be able to put everything back.

When it jammed, did you notice if you could see the black elastic in the ejection port? You shouldn't be able to see it in there. The elastic on mine slipped in between the bolt and the upper receiver which locked up the bolt. That happened when I inserted the bolt carrier group into the receiver without keeping the elastic taught.

[sushi_boy604]

I don't remember but I do remember taking it out while inspecting the gun. I'll keep on eye on it. Thanks.

Originally Posted by SKI

When it jammed, did you notice if you could see the black elastic in the ejection port? You shouldn't be able to see it in there. The elastic on mine slipped in between the bolt and the upper receiver which locked up the bolt. That happened when I inserted the bolt carrier group into the receiver without keeping the elastic taught.

[Rookie Ab]

Originally Posted by sushi_boy604

As for the receiver, does anyone know if its easy to install the internals? My fear is once I get my replacement, I am afraid that I won't be able to put everything back.

You did take notes of the order they come out and took a few pic,s of the way the springs were in there. didn't you. It's fairly simple once you get in there and start putting it back together.

[sushi_boy604]

Yeah I will. I learned that the hard way after taking apart my my KSC 19 hammer spring lol Thanks for the advice.

Originally Posted by Rookie Ab

You did take notes of the order they come out and took a few pic,s of the way the springs were in there. didn't you. It's fairly simple once you get in there and start putting it back together.

[andrew321]

So when they say make sure the O-ring piston head is locktit-ed, do so...Mine came loose and mauled my piston cup. Kept firing though,

I wouldn't mind getting another bolt assembly as a backup.. Is there somewhere I can order KJW parts? Their site seems to be in construstion indefinitley.

[SKI]

I used blue loctite on mine and it still came loose. I just did it again using a little more loctite this time. I hope she holds.

[sushi_boy604]

I was able to fit:

• Madbull Daniel Defense Omega 7 inch without modification. It was a tight fit. Took 10 minutes to install.
  
• Madbull XM203-S BB Launcher.
  
• King Arms OPS Model 3rd MBS Silencer (230mm)

I have pictures that you can look at too at:http://www.airsoftcanada.com/album.php?albumid=160

The gun came to me with a crack in the lower receiver near the buffer tube on the left side (selector switch). Jeff was kind enough to ship me a new lower receiver replacement. Replacing the receiver was easy and fun. The layout of the springs were not difficult at all and the trigger system consisted of 3 parts. If you need to know the details, PM me and I can help you with that.

The gun itself feels a lot heavier and bad-ass looking than the stock. The King Arms silencer turns out to muffle a bit of the sound, which I am quite amazed with since it is usually just for show and concealing of an extended inner-barrel.

I am still waiting for internals since Jeff is bringing in some cradleairsoft.com products. I am also waiting for the foldable rear and front sights. They will be used when I decide to get an Eotech holographic sight. Is it highly recommend ed to get the lens protector?

A really fun GBBR to play with. I love firing 30 rounds on full auto. Cool-down factor is great but everyone should know that. The launcher itself is alright. It does the job.

Things to add to the gun would be a 3 point sling, flashlight, and rail covers.