KJW M4

[Leshy]

Great, look forward to it bank balance allowing i'll be having one.

[D2D]

Hey guys - I got the KJW M4 not even a full day ago, and it's really starting to screw up on me. The bolt carrier is worn to hell, and the bolt catch is slipping from the tab and getting stuck in a recess, preventing the release of the bolt. Here are some pictures to explain - http://imgur.com/a/9y2jF#0

 

Surely this isn't a normal level of wear, especially in one day? I put this gun through maybe 1.5 magazines, if that. The rest of the gun is in good shape.

 

Has anyone had this problem before? I tried searching, but couldn't find anything.

[Hut73]

Hey guys - I got the KJW M4 not even a full day ago, and it's really starting to screw up on me. The bolt carrier is worn to hell, and the bolt catch is slipping from the tab and getting stuck in a recess, preventing the release of the bolt. Here are some pictures to explain - http://imgur.com/a/9y2jF#0

 

Surely this isn't a normal level of wear, especially in one day? I put this gun through maybe 1.5 magazines, if that. The rest of the gun is in good shape.

 

Has anyone had this problem before? I tried searching, but couldn't find anything.

 

The wear does look similar to what some others have reported with their v2 bolt setups, but it certainly seems odd after only a mag and a half.

[Kai_Wolf]

PM inbound Thum

[t_hum]

Hey guys - I got the KJW M4 not even a full day ago, and it's really starting to screw up on me. The bolt carrier is worn to hell, and the bolt catch is slipping from the tab and getting stuck in a recess, preventing the release of the bolt. Here are some pictures to explain - http://imgur.com/a/9y2jF#0

 

Surely this isn't a normal level of wear, especially in one day? I put this gun through maybe 1.5 magazines, if that. The rest of the gun is in good shape.

 

Has anyone had this problem before? I tried searching, but couldn't find anything.

 

I haven't seen one wear quite this quickly before. I had a brand new gun in last week for some mods. Seemed to me like it was wearing faster than I expected. We got a few mags through I to test all the mods and the carrier was wearing in the bolt catch area as well. I had to do some filing to get off a sharp edge or two that I thought might cause potential issues.

 

I really wish KJW hadn't ditched the proven and mature TK design for the carriers. Our new carriers are a throwback to the original design and should be even more bulletproof than the originals.

[D2D]

What's weird is that there is no corresponding amount of wear on the rest of the gun. The retailer chronographed the gun before shipping, so maybe some jerk decided he wanted a new bolt carrier for free? Who knows. What's the bolt carrier made of, anyway?

 

I've put in a stop-gap measure - I put on multiple layers of tape on the bolt catch to stop it from going too far up and slipping off the tab. It's working reliably; for now.

 

Anyways... How should I store this gun? Cocked and on safe, or decocked and on semi? Seems like if I leave it cocked, the hammer is under tension, but if I leave it decocked, then the valve knocker is under tension. Which is better? Also, is it safe to dry fire without a magazine? I apologize if these questions are common knowledge, it's my first airsoft gun.

Edited April 4, 2012 by D2D

[D2D]

I can't find the edit button, so I'll just double post.

 

I have discovered an interesting malfunction while playing with my fix mentioned above. If the wedge is just slightly too thick, the bolt will release itself automatically as soon as a new magazine is inserted.

Edited April 5, 2012 by D2D

[frogfish]

I'm sorry to hear that Hut, didn't you have another KJW sitting around somewhere though?

 

 

Here is my KJW training weapon built like my real one, well, minus the peq, and the KJW's barrel is 1.5 inches shorter........

 

Edited April 5, 2012 by frogfish

[Hut73]

I'm sorry to hear that Hut, didn't you have another KJW sitting around somewhere though?

 

 

Here is my KJW training weapon built like my real one, well, minus the peq, and the KJW's barrel is 1.5 inches shorter........

 

Frog, looks great!

 

I still have my primary. I was gonna use this to build an upper to swap in and out that mimic'd my RS. But just don't have the time or energy right now. I'm not selling the primary, yet anyway...

[frogfish]

Ok so now that two retailers have had my money for over two months waiting to re-stock classic army ready mags, I'm getting a bit disgruntled, does anyone know where I can find one ( preferably in the states), or conversely how much work does it take to make the g&g or g&p work?

 

Edit: I know AEX dosen't have them, and neither does Combatsupportsupply

Edited April 6, 2012 by frogfish

[weekenny]

The g&p is too small and tight.

[D2D]

Question: how much play should there be between the guide rod and the bolt carrier? I'm starting to think that excessive play is the source of all my problems with this gun.

[t_hum]

I finally got the v2 disassembly/installation video done.

Link:

[Bastel]

Is it right that the V2 Boltcarrier isnt as good as the v1?

[Kai_Wolf]

My v2 bolt definitely does not perform as my v1 did. My v2 for some reason isnt as crisp when fired.

[frogfish]

But its still not poo, it works, well sometimes, when it dosen't work you can always help your target facepalm

 

BTW way where is the vid of that... We were both rocking KJWs it might be worth sharing...maybe...

Edited April 12, 2012 by frogfish

[Valkyne]

My v2 bolt definitely does not perform as my v1 did. My v2 for some reason isnt as crisp when fired.

 

Same here, my V2 likes to grind on the auto sear and the buffer retainer while charging the carrier. I've also discovered my V2 seems to fit very loosely in the upper receiver which can't be good. I put a few mags through it and imediately swapped back to the V1. I will continue to use my V1 until T_Hum releases his own model.

[Landa]

hey guys a indoor arena is opening up in the miami area finally, but there will be a strict 380 fps limit.

 

Im looking to make my KJW to be legal. Originally i was gonna get a second GBB, a KWA MP7 for that field... but I'm too poor right now.

 

So I'm getting some more mags and using the KJW, Currently its shooting 480-500 in the FL heat outside.

 

Im guessing the cradle velocity reducer? but i what to get a new inner too... and another bucking. Will buying a new bolt from KJW be good idea to quickly switch between full power and legal fps?

 

But, i read a couple of pages before (always following this thread lol) that a velocity reducer didn't have leave enough air to push the bb out a 509mm? will i have that problem... because the 509mm falcon inner is the only one in stock in ehobby.

 

Any suggestions?

[weekenny]

The cradle reducer is the best way to sort the FPS. A spare bolt is handy for quick swaps.

 

A 500 inner barrel? You plan to use a DMR style rifle at CQB??

[Landa]

The cradle reducer is the best way to sort the FPS. A spare bolt is handy for quick swaps.

 

A 500 inner barrel? You plan to use a DMR style rifle at CQB??

 

no the 509mm falcon 6.03 inner is the only one stock in ehobby. I have a silencer on it already, so it will fit... and i wouldn't mind it.. but ill rather a shorter 363 standard one... i need to find one.

[Leshy]

Cradle make custom barrels for the m4 if your stuck, cu from Madbull .03 or .01 i think!

[Landa]

Cradle make custom barrels for the m4 if your stuck, cu from Madbull .03 or .01 i think!

 

yea, i asked t hum ... sadly, he says they aren't available right now.

[freon]

hey guys a indoor arena is opening up in the miami area finally, but there will be a strict 380 fps limit.

 

Im looking to make my KJW to be legal. Originally i was gonna get a second GBB, a KWA MP7 for that field... but I'm too poor right now.

 

So I'm getting some more mags and using the KJW, Currently its shooting 480-500 in the FL heat outside.

 

Im guessing the cradle velocity reducer? but i what to get a new inner too... and another bucking. Will buying a new bolt from KJW be good idea to quickly switch between full power and legal fps?

 

But, i read a couple of pages before (always following this thread lol) that a velocity reducer didn't have leave enough air to push the bb out a 509mm? will i have that problem... because the 509mm falcon inner is the only one in stock in ehobby.

 

Any suggestions?

 

1. You don't need to mod anything to lower the velocity. Just switch to some good 'ol 134A gas.

2. If you change your barrel to a longer one, expect an increase in FPS, and with gas rifles, this can be quite dramatic.

[Landa]

well i got some duster gas today in home depot, couldn't find the 134a...

 

but i got some 152a which is a different gas, but similar properties and can also be used in GBB's... only that the psi is a bit less.... 74 vs 95 psi.

 

what FPS do you think ill get in room temperature with the standard length barrel? (I'm gonna use it when i play indoors)

[D2D]

I thought I'd make a video of just some of the problems I've been having with my gun, and what I think is the source of all the malfunctions, which is the amount of bolt carrier wobble. Can anyone with a properly functioning gun tell me how much wobble is normal?

 

http://youtu.be/oHJNFWAJFnQ

Edited April 21, 2012 by D2D