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KJW M4

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OK the TDC modification, I'll keep the guide quite simple because its a simple enough modification and you can alter some of the details to suit (you'll see as we go).

 

You will need:

 

Drill, either a pillar drill or a normal drill in a stand.

Tap set.

Drill bits.

Center punch.

Calipers / Ruler.

Soft jawed vice.

 

Now before we start I drilled mine from the underside to the top, first attempt I went from the top down and the drill was off a little not enough to make the mod not work but I found working from the inside out made getting the buisness end spot on easier. To achieve this you will need a faily small chuck in the drill. Also make sure your tap is going to be long enough (you can do this from the top inwards).

 

As for what to use as a set screw I made mine from a 4 x 50 mm stainless bolt. Cut to length with a slot in the top for a small screwdriver.

 

 

Step 1: Strip the upper (on your own here, if you are stuck I did pictures for the shrink wrap mod.)

 

Step 2: Assemble the hop arm and carrier alone into the upper. Mark the position of the end of the hop arm (roughly the end of the ramp). Remove arm, etc.

 

Step 3: Mark with a centre punch half a diameter (of your selected set screw) plus 2mm back from the end of the arm mark.

 

Step 4: Grip your upper in a soft jawed vice so that the drill bit will pass squarely through the upper.

 

Step 5: Drill slowly through the upper, watch the material is soft but the guides for the gas tube can deflect the bit. I'd suggest a small pilot bit to start.

 

Step 6: Remove burrs from hole.

 

Step 7: Tap hole to suit selected set screw.

 

Step 8: Assemble you need the factory hop, arm / spring etc but you can bin the wheel, screw and the spacer ring thing.

 

Step 9: Set hop and enjoy.

 

 

Excuse the pictures they are from my first go where the drill deflected and as you can see the hole is off. But this did not cause the hop arm to skew so I'd not worry about being dead centre but it does look neater when you are done.

 

Screw.JPG

 

Home made set screw, very simple but you can use any grub screw (4mm is ideal)

 

Hole1.JPG

 

Hole2.JPG

 

As you can see my first go was a little off, also nearer the front end of the ramp would have been better.

 

Travel.JPG

 

Even with the hole a bit to the side the arm remains square right to the end of its travel as shown.

 

Top.JPG

 

What you see on the rail.

 

Dear sweet 8lb 4oz baby Jesus!!! Thats well outside of my paygrade. I'm more of a Wreck It Ralph than a Fix It Felix. Thanks for the guide though guys, I appeciate the effort. Plus it will help the person I pay to do this for me big time...

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I had a coworker help with mine, since im more into the fine tuning of things than power tools. He made it look easy, but yea the prospect of screwing up and leaving you with a huge hole in the upper is kinda scary. Hope you get it fixed, since its well worth it

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I got my Cradle V1+ yesterday, awesome package. I havn't shot with it yet, only to Chrono -the out of box FPS- which was roughly 140 m/s. The bolt is lighter, the action feels more crisp which i think it caused by the V1(+) design?

 

But due to the ligther weight i expect lesser recoil. Will write more after it has seen its first battle :)

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I've really enjoyed my V1+.

I got my speed loader today and it is a tight fit!.
My question is....is there a loader strong enough to force feed the thing?. I thought it'd be a bit easier. not quite sure how to work it. Maybe its just me derping out.

I have a King Arms loader.

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Ok guys... lets try this.

Tried out the V1+ bolt yesterday.

It ran good but there was some issues. First of - the Bolt didnt cycle all that well after trying it out with mag nr. 2. It might have been me, that didnt lube it well enough.

 

Also my hopup is way too inconsistent even though i have the TDC mod. I suspect it has something to due with the inner barrel allowing wobble, causing the some shots with hopup engadged, some with none at all.
I currently have a Madbull outer barrel installed, and its abit off spec compaired to the stock one. I will try putting on the stock outer barrel to eliminate the wobble/hopup issue. 

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after who knows how many shots, I noticed that my loading nozzle cracked. I tried to epoxy the crack shut, but the glue would disintegrate when I put rounds though it. epoxy doesn't seem to stick very well to the plastic. Should i try cleaning the area with soap to see if the epoxy will stick better? what about if I used a torch the melt the ends together?

 

Does anyone happen to have a spare that I can buy or know where I can get one without buying an entire v1+ from cradle? from what i've read on this forum, KJW does sell v1 parts anymore

post-91925-0-84445000-1367877754_thumb.jpg

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after who knows how many shots, I noticed that my loading nozzle cracked. I tried to epoxy the crack shut, but the glue would disintegrate when I put rounds though it. epoxy doesn't seem to stick very well to the plastic. Should i try cleaning the area with soap to see if the epoxy will stick better? what about if I used a torch the melt the ends together?

 

Does anyone happen to have a spare that I can buy or know where I can get one without buying an entire v1+ from cradle? from what i've read on this forum, KJW does sell v1 parts anymore

Sorry man. I just saw your response over on gasguns. I just happen to have one spare left. Pm me when you have a chance.

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after who knows how many shots, I noticed that my loading nozzle cracked. I tried to epoxy the crack shut, but the glue would disintegrate when I put rounds though it. epoxy doesn't seem to stick very well to the plastic. Should i try cleaning the area with soap to see if the epoxy will stick better? what about if I used a torch the melt the ends together?

 

Does anyone happen to have a spare that I can buy or know where I can get one without buying an entire v1+ from cradle? from what i've read on this forum, KJW does sell v1 parts anymore

Yeah my old one cracked in that same spot too! I used eproxy and super gorilla glue to fixed it, but after 150-200 rounds the glue came off. I end up buying the complete V1+  from Cradle for $160. The best solution is, try to order a new loading nozzle directly from Cradle.But I'm not sure if they'll sell you just the nozzle. Good luck!

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Yeah my old one cracked in that same spot too! I used eproxy and super gorilla glue to fixed it, but after 150-200 rounds the glue came off. I end up buying the complete V1+  from Cradle for $160. The best solution is, try to order a new loading nozzle directly from Cradle.But I'm not sure if they'll sell you just the nozzle. Good luck!

Cradle does not because they are hard to come by apparently. Gotta buy the entire V1+

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Hey everyone, I just finished reading some 200+ pages on this topic, and has me second guessing my purchase of kJW M4 cqb-r. I mean I sold my WE M4 cqb-r and HK416 because of their reliability issue, and now I'm not to sure if KJW V2 will fair any better. Is the V2 really that bad compared to V1? I honestly don't care about the realism of the BCG, as long as I could field the gun I'm happy. I guess my first purchase is the Cradle BCG and try to modify RS charging handle to replace the stock charging handle. 

I'm guessing I'll hold of on the hop-up till I test it when I get my gun on Monday.

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Hey everyone, I just finished reading some 200+ pages on this topic, and has me second guessing my purchase of kJW M4 cqb-r. I mean I sold my WE M4 cqb-r and HK416 because of their reliability issue, and now I'm not to sure if KJW V2 will fair any better. Is the V2 really that bad compared to V1? I honestly don't care about the realism of the BCG, as long as I could field the gun I'm happy. I guess my first purchase is the Cradle BCG and try to modify RS charging handle to replace the stock charging handle.

I'm guessing I'll hold of on the hop-up till I test it when I get my gun on Monday.

To be honest, the whole thing with the charging handle seems to be really hit or miss honestly. And the v2 on the whole seems to perform well in its stock configuration. It's when you start mixing v1 and v2 parts that minor problems seem to arise. The cradle bcg bridges that gap.

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I just received my KJW M4 cqb.

The exterior finish was not what I was expecting. To plastic looking and shiny, and I cant really tell if its metal or plastic. Overall the gun is lighter than my We m4 cqb, which is a plus. The internals are very simple and looks easy to work on.

I cleaned the internals and applied some frog lube(great stuff). Took it out and emptied about 4 mags, and so far the hop-up seems to be working just fine. didn't notice and excessive wear on the BCG. but their is small chip on nozzle, where the mag gas release kisses the nozzle.(not share if that made sense). 

There was also a lot of wobble(RIS, stock,&upper and lower receiver), easily fixed with good old electric tape.

I used 134a gas and was averaging 340-360 fps with .20g, and 320-340fps with .25(great for indoors)

Recoil wasn't as hard as my WE M4, but my fps was consistent(cant complain)

Now all I need is 4 more mags and I could take her out for a spin.

 

Thanks everyone for this awesome topic. 

Here is what it looks like with some furniture.

WP_20130513_001_zpsc624b8e7.jpg

Edited by su37su

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Be careful with the frog lube, it can and will freeze, causing issues, its better to stick to a non-temperature sensitive lubricant, especially one without carbon leeching qualities, like super lube.

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Be careful with the frog lube, it can and will freeze, causing issues, its better to stick to a non-temperature sensitive lubricant, especially one without carbon leeching qualities, like super lube.

Haven't had any issues with my other gbb's so far, but Thanks, I didn't know that. 

 

Is this what you're referring to?

http://www.walmart.com/ip/21074842?wmlspartner=wlpa&adid=22222222227000000000&wl0=&wl1=g&wl2=&wl3=21486607510&wl4=&wl5=pla&veh=sem

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I think so though I've never seen it at walmart, you can also use the high grade lube that cradle airsoft sells it is very effective.

 

 

Temperature sensitivity is the biggest failing of organic CLPs like Froglube as it can "stick" in cold temperatures and it burns away when the weapon gets hot.

Edited by frogfish

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So I've found out that the RA and Falcon rubbers just suck, even with the TDC mod. I ordered 8 Falcon rubbers just to find out they're designed entirely different than the stock Part#20

One, the hop nub is more towards the front of the rubber, while the Part#20 nub is in the middle of the rubber, the hop arm is having trouble contacting the hop nub on the Falcon, as well as the nub being way too oversized.

Slight remedy to this. Dremel down the oversized hop nub on the Falcon rubber to about the size of the nub on the stock Part#20. Not perfect, but will subside.

Contact KJW for the spare parts you're having trouble finding. I ordered my Part#20s from KJW direct, $14.90 (for 2 #20s and S+H) later, and they'll be here (U.S.) soon.

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So I've found out that the RA and Falcon rubbers just suck, even with the TDC mod. I ordered 8 Falcon rubbers just to find out they're designed entirely different than the stock Part#20

 

 

One, the hop nub is more towards the front of the rubber, while the Part#20 nub is in the middle of the rubber, the hop arm is having trouble contacting the hop nub on the Falcon, as well as the nub being way too oversized.

 

 

Slight remedy to this. Dremel down the oversized hop nub on the Falcon rubber to about the size of the nub on the stock Part#20. Not perfect, but will subside.

 

 

Contact KJW for the spare parts you're having trouble finding. I ordered my Part#20s from KJW direct, $14.90 (for 2 #20s and S+H) later, and they'll be here (U.S.) soon.

Yeah, it's been known for quite a while that they're both in comparison to the stock ones.

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I'm easily getting 150ft with three rings on the reducer and .43s, but the grouping could be way better. Can't stand black BBs though. That aside, there's just no way anyone could ever convince me to go back to a WE M4, or anything else for that matter, after having her for more than seven months.

For those reading this thread, and you're thinking about buying a KJW M4, do yourself a favor...and buy one!! I broke the loading nozzle spring and she still kicked butt. And all I had to do to fix that problem was bend a new coil off the spring, bent two as matter a fact. I've had some issues with my V.2 BCG, but somehow they've mainly worked themselves out. Just had to be broke in I guess. Bolt locks back on empty, every time; no longer jams on the last BB. And the bolt catch works now without a new magazine being inserted and releasing the bolt catch on it's own.

After a few failed mod attempts, and some successful ones, I'm in love all over again. She has the serious potential for first shot, one kills within a certain "long distance shooting" range (of course), as even my G&G SR-25 with it's 6.04 TB, a Systema rubber, and Bioval .40s couldn't acheive this, though it had some great range at 240ft, but the grouping was terrible. I foresee the new Part#20s turning her into what I wanted from my KJW M4, a [reliable] AR gas-replica DMR platform.
 

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Hi guys,

 

I bought this gun just last week at Redwolf with another 5 mags, Troy TRX rail and Ratech inner barrel (for KC02 gun, but 363mm and sit in perfectly)

I played with it at the last weekend day and night. It was around 18°C during the day and around 10°C at midnight. Filled with Greengas. During this game I put throug it around 500 BBs (BLS 0,30g).

The feeling from this gun is very good, just mine has few flaws:

 

1. the upper and lower receiver has slight woble to side (or to describe it better, it is like a rotating movement around axis in way of barrel). It´s about 0,5-1mm. I think is not very obvious. I read plenty of reviews, even here I read more than hundred pages of this topic and nobody had this kind of woble. Mine is version two, with the BCG without the rubber band.

 

2. after game I looked on mags and I found that there is a small damage on top side, probably from BCG.

 

mag_dmg.jpg

 

on BCG it´s some damage too:

BGC_dmg.jpg

 

I´m little bit afraid what will happen after few other games. In the other way, I still have PTW, so no problem if this will fail, but I want run with this gun. It´s amazing. It´s lighter then my systema M4, but mostly because I have on PTW Ready mag with second mag inside (another 1kg). And of course gas is something totaly different. I think all of you know it very well.

 

OK so next thing:

3. two mags leaks the gas from bottom valves. One of them needed only to be tighten more, another one I had to replace the valve (fortunately I had another one). I found this when I measured the gun on chrono - first mag go through with 0,20g BBs from 137-143 m/s (without any big difference in speed for every next shot). Second one with 0,30g BB in from 128 to 115 m/s where every shot was slower.

- replaced and done. I will see what will happen with all six mags after few weeks, when I will go to next game.

 

4. pins which holds receivers together go out very easy. And other pins in lower receiver too. I thinking about to glue those. Or when I will paint the gun, maybe the paint will glue it a bit.

 

Gun shoot very good (measured 65 meters, but the hop up is not setted perfectly yet), sounds very good, handling is very easy...

 

As I wrote before, I put inside longer TB from RaTech (363mm) and installed Troy TRX 7" on it. It´s very easy, all fits perfectly.

 

But I had problem to assembly Magpul ASAP. I cannot unscrew the part on tube. I broke my wrench from G&P on it (is toothless now).

 

 

I bought for it a new case from Berwall.de. It´s a double side case (in other side lying PTW).

KJW%2520in%2520berwahl.jpg

 

 

I must say I like very much Thremold mags. They looks different, I hate all those simple Stanags, or famous P-mag. Everybody have them.

I was just affraid if they fit into my pouches, but without problem. Even in those plastic fast mags holders. I crawled with them few times and I didn´t lost any.

KJW_Grom.jpg

 

Thank you all for this perfect topic. I read about this gun a lot last two years, finnaly I had now enough money to buy it. Hope it will run long time without problems.

Edited by lordtoreador

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1. the upper and lower receiver has slight woble to side (or to describe it better, it is like a rotating movement around axis in way of barrel). It´s about 0,5-1mm. I think is not very obvious. I read plenty of reviews, even here I read more than hundred pages of this topic and nobody had this kind of woble. Mine is version two, with the BCG without the rubber band.

If your referring to your upper and lower receiver not fitting tightly, like I think you are trying to say, this is not uncommon after a while of use. I know you said you bought this from Redwolf, but is it a used gun? I would think it would take longer than just one game for it to loosen up. I recently purchased a V1.1 from someone on my home forum, and mine has a slight "wobble" too. I don't notice it much since it is identical to my real AR. ARs aren't super tight.

 

3. two mags leaks the gas from bottom valves. One of them needed only to be tighten more, another one I had to replace the valve (fortunately I had another one).

You probably would have gotten away with opening the mag up, cleaning the valve and o ring, packing it with some silicone grease and then reassembling. These mags are pretty impervious to leaking, when clean and properly lubed.

4. pins which holds receivers together go out very easy. And other pins in lower receiver too. I thinking about to glue those. Or when I will paint the gun, maybe the paint will glue it a bit.

Hopefully the paint helps to get the pins to retain better. Gluing them just sounds like a bad idea. You may need to service something some day, if it's glued that will be difficult. Just to clarify, are you saying that your hammer and trigger pins are trying to walk out? Or is it just the pivot pin and takedown pin?

 

Gun shoot very good (measured 65 meters, but the hop up is not setted perfectly yet), sounds very good, handling is very easy...

Are you having inconsistent hop, or is it constantly under hopping? Also, what weight BBs are you using? One thing that is always a good idea, is to take your hop up apart and clean the bucking (or rubber as I keep seeing people mention on this forum). Clean it with soapy water, then rinse it and let it air dry. Reassemble after cleaning your barrel as well, and try not to get any silicone on the bucking. As long as the bucking had oil on it, you will not get consent hop performance.

 

But I had problem to assembly Magpul ASAP. I cannot unscrew the part on tube. I broke my wrench from G&P on it (is toothless now).

 

Do not try to take the receiver extension (buffer tube) apart the same way you would on a real AR. It is not built the same. Instead remove the stock from it, look on the bottom of the "buffer tube" for a small hole. This hole has a set screw in it that you need to loosen. Next you need to unscrew the very large slotted bolt at the back of the "buffer tube". You can use the back side if a butter knife to accomplish this. From there, a couple people in this thread have suggestions on how to rig up the assembly. It's not too straight forward. Your other option is to order the CQB version's receiver end plate. It isn't like the ASAP, but it does have a sling mount built it.

 

The ASAP mounting instructions, I think, are somewhere in the last 80 or so pages. I just got done reading the 281 pages myself.

 

 

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