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KJW M4

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You already busted your front receiver tab? :(

 

Yeah, sucks, huh? Right now it doesn't seem to be affecting anything. Didn't you or someone else have some temporary/ghetto reinforcement?

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Well, since no one else really seems to know how to mod a UBR to a KJW m4, I will take the stand.

 

I just ordered an ACM UBR through T-Tiger on ASF, and when it comes I will do a full HOW-TO on modding a UBR (AEG Type) for your KJW m4. I was frustrated that no one had made a DIY for it, and I'm sure many others have been before me. However, hopefully by next week I will have a full how-to for this application.

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Well, since no one else really seems to know how to mod a UBR to a KJW m4, I will take the stand.

 

I just ordered an ACM UBR through T-Tiger on ASF, and when it comes I will do a full HOW-TO on modding a UBR (AEG Type) for your KJW m4. I was frustrated that no one had made a DIY for it, and I'm sure many others have been before me. However, hopefully by next week I will have a full how-to for this application.

 

I've been running a UBR for months now.Because it is just a (temporary/ghetto) install, didn't think anyone was or is interested. Page 61 back in Dec I posted a pic.If you want, drop me a line and I'll tell you how I did it. Quit simple,not duct tape and tie wire but close :P

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Lol, yeah I have a very good idea about what I'm going to do this evening and tomorrow to get it all working. Thanks for all the info. I'll post up a Co-DIY that will give both of us credit maybe at the end of the weekend or something.

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Lol, yeah I have a very good idea about what I'm going to do this evening and tomorrow to get it all working. Thanks for all the info. I'll post up a Co-DIY that will give both of us credit maybe at the end of the weekend or something.

 

 

I can't edit my post anymore, so I'll just post again...

 

I just finished modding my ACM UBR. It was really easy.

 

 

Thanks to Rookie Ab for helping me out with this and giving me some great ideas this week!

 

This guide works well for all UBR's made to work with AEG's (AEG type buffer tubes), if you have one thats meant for a gas blow back rifle (has threads on the buffer) read the extra step.

 

 

1.) Unscrew the grub screw from the bottom of your original stock tube, after removing the stock you had on the tube beforehand. Also, at the time remember to remove the buffer and buffer spring from your buffer tube.

 

2.) Unscrew the rear cap from the stock tube. If you're is stuck, try using some Vice Grips and then turn them while they're clamped on to the cap. This should give you the friction you need and is way better than using some ridiculously big flat head screwdriver on that enormous cap. Once you've gotten that off, slide off your old stock tube which should expose the brass inner buffer tube unique to only KJW's.

 

GBBR Threaded Buffer Tube EXTRA STEP: If you've got a GBBR UBR, you're going to need to wrap the brass buffer tube in some kind of heavy duty tape in order to beef up outer diameter. Since you can't use the UBR buffer tube, you're going to need to translate the UBR parts onto the original KJW buffer. I have not done this so I don't know how, but you can PM "Rookie Ab", as he has utilized this method.

 

3.) Now that you're ready to slide on the UBR buffer tube, you'll realize if you do this, there is a gap between the buffer and the receiver. This can be covered up in some electrical tape, or any other black tape. I used Gorilla Black Duct Tape, and it worked just fine. Keep test fitting the tube to make sure the tape doesn't stop the tube from coming all the way forward, and to see if you've covered up the gap enough.

 

4.) This is the fun part. Take a #8 or 5mm drill bit. Screw the end cap onto your brass insert WITHOUT THE UBR TUBE ON IT (duh, you can't!). Once its on nice and tight (its not coming off again baby, better make sure its tight) place the UBR buffer tube over the end cap and and brass buffer tube. Put the #8/5mm drill bit onto your favorite powerdrill and use the hole from the UBR buffer as a guide and drill through the end cap.

 

5.) After you've drilled the hole, remove the UBR buffer tube, exposing the brass buffer tube, and take your handy dandy tapping tool, and tap an M6 x 1 thread into the hole you've made. You have now made the correct threading for the screw you need to insert into the back of the UBR to hold it in place.

 

6.) Take your M6 x 0.75" long black screw (with one of those angled heads.. forgot the name of them right now) and screw it through the UBR buffer tube, and into the now tapped end cap that is sitting on your brass buffer tube. It should be super sturdy now, and even sturdier after you screw in the screws that hold the cheek piece over the UBR buffer tube.

 

7.) Slide the UBR stock onto the UBR buffer tube system, and bam, you're done!

 

 

Took me about 35 minutes!

 

Pics later.

Edited by wdahm519
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Quick Update On The 'Buffer MOD'

 

As Some here would know I decided to 'MOD' my gun to facilitate the use of Single Point Attachment Stock Receiver End Plates Such As the Magpul A.S.A.P. Plate.

 

I have been running the KJW M4 in this configuration now for 2 months now and have found the best Reliable configuration.

 

 

Mil Spec Buffer Tube MOD = Buffer Tube, A.S.A.P. Plate, Buffer Tube Castle Nut,

Winter Weight Spring

Mil Spec Buffer Modified to Non Moving Internal Weight of 62 Gram Total.

GEN 1 Carrier Weight Removed ( NOT Present if you have Later Model KJW M4 )

 

With the Above Configuration the gun runs very well and feels great to shoot with!

 

 

Using the 'Winter Weight' Action Spring which is Very Near the same Tension as the Factory KJW Action Spring the gun have a definite increase in felt recoil. This is due to the larger diameter Buffer being moved inside the buffer tube. At first I did leave the buffer weights freely moving inside the buffer and the recoil was stronger still.

 

I have a GEN 1 KJW M4 as mine arrived with a serial # etched on the side. This KJW M4 came equipped with a Weight installed into the carrier ( The NEW Model KJW M4s DO NOT Have This Weight In The Carrier ) When testing this carrier weight was installed on the carrier as it had always been.

 

BUT, to keep the gun as reliable as possible I made the Buffer weights inside the buffer fit tightly with No Movement - Just Like the Solid Metal Factory KJW M4 Buffer.

 

There is felt recoil Increase and the gun runs reliably and shoots crisply.

 

Below IS For Reference:

Mil Spec Buffer Weight = 84 Grams

KJW Factory Buffer Weight = 62 Grams

AABB Aluminum Speed Buffer = 50 Grams

 

At first I ran the gun with:

Summer Weight Spring

Mil Spec 84 Gram Buffer

 

Felt Recoil Was INCREDIBLE - Stronger Than Factory WA - but the Bolt Catch Broke after a few times of locking the bolt back! Also please note that the GEN 1 carrier weight was still present in the carrier.

 

So This Configuration Was A No Go For Me!

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Checking in

 

~16,000 rounds spent through the gun...broke a third rubber band (from day one) at a game today where I got a crapload of kills shooting legs (and butt) from underneath the yellow bus at CQB City in Stockton, CA. I still have 7 so I'm good for another 35,000 rounds or so :P

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I made the leap of faith last week and decided to get a KJW M4 CQB-R via Airsoft Advantage's WGC Shop Special Order. Here's hoping that customs doesn't nab it! After doing some research and experiencing the suckage that is the WE SCAR, I went for the KJW platform. Based on everything I've read here, it sounds like it was the right choice.

 

I have a few issues though:

 

Where are the mags? It seems like every major retailer I know of has them out of stock. Was production cut at the source? I'm a bit anxious because I have no idea if KJW is going to make more of them - does anyone have any insight as to when we can expect to see them replenished at stores? A shame it would be if I end up with the one stock-skirmishable GBBR on the market, only to have just one mag!

 

Given the situation with the magazines, I am also worried I won't be able to get spare parts. I understand that some of you have gone through Clare at KJW to get stuff like hop-up buckings and spare rubber bands; these things are essential consumables to keep spares of. Can anyone confirm that KJW is still taking orders for spare parts through Clare's email address? (I ask only because I haven't tried yet.)

 

Thanks for your help.

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Great stuff in this thread, I'm loving how everything is working out for you guys!!!

 

Can anyone here give me the weight(in grams preferably) of the stock carrier(new version w/o weight).

 

Also, Bnarboots333, just wait if you cannot find mags in stock. You might be surprised at what comes out.

 

Thanks,

 

-Luis

Edited by Luis21

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Where are the mags?

It seems that the KJ rifles and their magazines are selling like hot cakes, which isn't really a surprise given how ridiculously awesome these guns are, compared to any of the competition. Last week the magazines came back in stock in eHobbyAsia (and I ordered 4 more), and only after a week they are sold out. Same thing I've seen in every other store. It seems that the shops are not getting enough of them to meet the demand. So you need to be fast when you see them in stock somewhere.

 

About the KJ spare parts: I just recently ordered some parts from Clare (rubber bands, hopup rubbers and bolt stops), and last week I received the package. So they still sell them. But be patient, it might take few days before Clare answers your parts quote.

 

PS. I think the really weird thing is that none of the shops have ordered larger amounts of spares and started selling them. There should be a demand for this kind of service. This KJ approach through Clare is a bit "complicated" and no-one not following this thread would even know about it...

Edited by Lupus78

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Where are the mags? It seems like every major retailer I know of has them out of stock. Was production cut at the source? I'm a bit anxious because I have no idea if KJW is going to make more of them - does anyone have any insight as to when we can expect to see them replenished at stores? A shame it would be if I end up with the one stock-skirmishable GBBR on the market, only to have just one mag!

 

Given the situation with the magazines, I am also worried I won't be able to get spare parts. I understand that some of you have gone through Clare at KJW to get stuff like hop-up buckings and spare rubber bands; these things are essential consumables to keep spares of. Can anyone confirm that KJW is still taking orders for spare parts through Clare's email address? (I ask only because I haven't tried yet.)

 

Thanks for your help.

 

Let's not speculate... something as of this could spark a rumor; and which is not true. So let's keep this sort of stuff down. Simple Questions - Like "Are Magazines still available anywhere?" is fine... but a Question like "Was production cut?" will cause some people to speculate and go for the worse deals AKA- WE, INOKATSU, WA, G&P.

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Let's not speculate... something as of this could spark a rumor; and which is not true. So let's keep this sort of stuff down. Simple Questions - Like "Are Magazines still available anywhere?" is fine... but a Question like "Was production cut?" will cause some people to speculate and go for the worse deals AKA- WE, INOKATSU, WA, G&P.

 

That certainly wasn't my intent; I was just thinking of a scenario and inquired, directly, as to its plausibility. My post was supposed to be less speculation and more an honest question - though I understand your concern. Thankfully, the idea seems to have been disproved based on the recent restock at eHobby.

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Would someone with an original box be willing to do me a favor and measure its dimensions (height x length x width) for me? This is the box, not the gun. Thanks in advance!

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I have finally managed to snap some pics on my KJW M4 with its new accessories, sorry for the grainy-ness of the photos, it would seem that my camera is getting old and tired:

 

IMG_2641.jpg

 

IMG_2648.jpg

 

IMG_2649.jpg

 

 

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I am ordering my KJW GBBR on friday if all goes well and they don't get sold out. I am going for the cqbr version and buying the Cradle airsoft upgrades. I never worked on an aeg, would installing the upgrades be something I can do even though I never did an aeg?

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I am ordering my KJW GBBR on friday if all goes well and they don't get sold out. I am going for the cqbr version and buying the Cradle airsoft upgrades. I never worked on an aeg, would installing the upgrades be something I can do even though I never did an aeg?

 

Yes!

 

The Cradle parts are simple to install and only take minutes to complete the work. There is a tutorial video on the website that is available if you get stuck.

 

You will find that ALL GBBRs are not as difficult to work on as an AEG as there is much less moving parts.

 

Congrats on purchasing the KJW CQBR - You're Going To Be Very Satisfied,,,

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Hey does any one happen to have a tutorial or pics on hopup disassembly. I disassembled my upper a couple days ago to install a new RIS and afterwards the hop up was nonfunctioning. Also, when u complete a revolution on the hopup dial does it reset?

 

And finally. Has anyone actually installed a VSR-10 barrel with true sucsess and a improvement in accuracy with out modification?

Thanks all

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I've managed to solve my hopup lever problem :) Thank you guys!

 

Range is now more then acceptable. I've measured 70m effective range with green gas and fully open setup (without any spacer on t_hum's velocity reducer) and 363mm 6.03 TBB. So, gun is over 500fps.

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Hey does any one happen to have a tutorial or pics on hop-up dis assembly. I disassembled my upper a couple days ago to install a new RIS and after wards the hop up was non-functioning. Also, when u complete a revolution on the hopup dial does it reset?

 

And finally. Has anyone actually installed a VSR-10 barrel with true success and a improvement in accuracy with out modification?

Thanks all

 

The hop up is made of 5 pieces. The hop-up rubber, Barrel, 2 Metal pieces that clamp over the rubber and barrel, and then a brass ring that goes over the 2 metal pieces. It's so much more easier than AEG hop-up units. Just make sure after its all together that when you press down on the rubber that the nub on the inside is straight with the barrel.

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