KJW M4

[wdahm519]

on a similar vein, what tool is needed to remove the grip. the allen keys i have are too short to reach the screw

 

 

A long allen key.. You can't really use much else. Just buy a cheap set at your local hardware store (support local business!)

[sacairsoftsn00py]

Got a Madbull outer barrel for an M733. The barrel is adjustable (so you can make sure that the hop unit is securely in place by pushing in the front part of the outer barrel to the base. Down side to it is that you will not get the right length for the hand guards that you're using. If you're using a free floating RIS, then this would work perfectly for you.

 

At the moment I am using o-rings as spacers to push the hop unit back) to secure it in place. This way, there will be no front to back movement which could affect feeding and shot trajectory.

 

Right now my shots are as consistent as they are with the stock outer barrel.

 

Either tomorrow or Monday, I'll install the Madbull Noveske 10" free floating rail on my M4 along with a Socom Gear Noveske Amplifier. With the installation of these parts, I will no longer need an 0-ring to hold the hop unit securely in place. I'll just adjust the outer barrel to where it pushes against the hop unit.

 

For those wondering about the Madbull M733 outer barrel...here's a little info on it:

 

-Adjustable (up to 1cm of extension)

-14mm CCW threads (I looked everywhere and saw that there was no mention of thread direction so here it is!)

-Aluminum. Light weight. Easy to cut.

-Noveske trademark at the front .5" of the outer barrel.

-Allows for about .5" or 13mm inner barrel extension inside the outer barrel (without the inner barrel sticking out).

---------

 

Edited November 6, 2009 by sacairsoftsn00py

[wdahm519]

That rifle needs to be blessed by Magpul....

 

How'd you make a non-L ARMS #40 fit under an ACOG?

Edited November 7, 2009 by wdahm519

[t_hum]

In case anybody is wonder how PTS CTR stocks fit: ROCK SOLID. Fit is very firm. Zero wobble anywhere.

[sacairsoftsn00py]

 

SOCOM Gear KX3 Amplifier

Madbull CQBR Outer Barrel

Madbull Noveske 10" Rail System

Magpul CTR

G&P 4x32 ACOG replica

 

No BUIS yet....just the one on top of the ACOG.

 

It was a tad longer than what I expected at 28" with the stock fully retracted. Oh well. At least the inner barrel is supported and not sticking into the KX3.

[wdahm519]

Now thats more like it Sac. Just throw a MIAD on there and it'll be golden!

[sacairsoftsn00py]

Was out plinking with this thing today and the rubberband snapped on me. I jerry rigged it by sewing it together. Its worked the past 100 rounds. Will put more rounds through it in a couple of days to see how well it holds up.

 

I sent KJ an e-mail requesting for a few replacement bands. I am waiting to hear from them.

 

MIAD grip will come in later most likely. I have not decided which optics I would like to use. I'm thinking about going with an EOtech. I'm not quite sure yet. For now, the pistol grip works as well as the ACOG.

Edited November 7, 2009 by sacairsoftsn00py

[A Tobias]

Was out plinking with this thing today and the rubberband snapped on me. I jerry rigged it by sewing it together. Its worked the past 100 rounds. Will put more rounds through it in a couple of days to see how well it holds up.

 

I sent KJ an e-mail requesting for a few replacement bands. I am waiting to hear from them.

 

MIAD grip will come in later most likely. I have not decided which optics I would like to use. I'm thinking about going with an EOtech. I'm not quite sure yet. For now, the pistol grip works as well as the ACOG.

 

I'm sorry if this has been covered already but I thought I read earlier in this thread that the rubber band had no purpose.

I'm probably wrong but i thought that on some guns it snapped and the gun still functioned.

What does it actually do?

Edited November 8, 2009 by A Tobias

[wdahm519]

I believe it prevents the cup from exiting out of its chamber too far and mushrooming.

[BrooklynBorn]

I'm sorry if I come off as an *albatross*, but I don't have time to read 50 pages.

 

What threading is the barrel? CW? CCW? And how easy is the flashider removal

 

 

EDIT: To sacairsoftsn00py- How easy was te fitment of the Noveske rail?

I'm thinking of either that, an ACM Larue Rail, or ACM URX. They all look great to me, but I just want whats easiest to fit onto there

 

EDIT 2: WHat would occur if when trying to convert an AEG barrel, the cut made is too large?

Edited November 8, 2009 by BrooklynBorn

[wdahm519]

There is no threading. Its just a set screw that holds it to a brass coupling.

[BrooklynBorn]

There is no threading. Its just a set screw that holds it to a brass coupling.

 

What do you mean? So you can't change flashiders or add a suppressor?

[wdahm519]

Not until t_hum produces new outer barrels, no.

 

You could possible shave the threadings off of another flashhider so it smooth inside (dremel would make that easy), and then slide it onto the brass coupling. There is still a set screw on most aftermarket flashhiders so you can secure it that way, or use glue and heat it up when you want to remove it.

Edited November 8, 2009 by wdahm519

[t_hum]

The brass insert comes off. It is threaded onto the barrel but held to the flash hider via a set screw.

 

I just fitted a 14mm CCW flash hider to test it and it seems to work.

[wdahm519]

The brass insert comes off. It is threaded onto the barrel but held to the flash hider via a set screw.

 

I just fitted a 14mm CCW flash hider to test it and it seems to work.

 

Whoa, good call. Did not see that coming!

[Raven1]

Range Report

Sunday, November 8th, 2009

12:00 Hrs 29C

 

!!Catastrophic Failure!!

 

Fired 6 Magazines through the gun and noted sluggish operation / movement of the bolt carrier group.

On last magazine fired noted bolt carrier group did not fully seat forward!

 

NOTE: In 10,642 BBs fired the Bolt Carrier Group Has NEVER Failed To Seat - Ever.

 

 

Inspection:

 

Upon breaking open the upper receiver the buffer (part # 53) shot out from the buffer tube!

 

Buffer spring (part # 74) was fully extended forward reaching onto the top of the magazine.

 

Found the broken remnants of the Buffer Retaining Pin (Part # 49) and the front section of the lower receiver.

 

That Is Correct - Lower Receiver Has Blown Out - No Longer Capable Of Holding The Buffer Retaining Spring / Buffer / Buffer Spring.

 

New Lower Receiver Is Required - There Is No Other Alternative!

 

 

Gun In Its Current Form - Primary Side

 

 

Gun In Its Current Form - Reaction Side

 

 

 

 

 

 

 

 

 

 

Ok Guys - You Know Me By Now Right? Right???

 

Well Then You Know I'm The Opposite Of Happy!

 

So What's A Guy To Do In My Position?

 

Exactly - I Reloaded 2 Fresh Magazines - Cleaned Out The Gun of Debris - Cleaned and Lubed The Buffer.

 

Shoved The Buffer Back In and Re-Assembled the Upper and Lower Receivers.

 

Please Note: Buffer Is Now DIRECTLY Resting On Back of Bolt Carrier Group!

I suspect this might be causing the gas inefficiency I was experiencing as the bolt carrier group is not moving freely during the beginning of its cycle causing the hammer to dwell longer on the magazine gas actuation valve. As normally the buffer retaining pin keeps the full pressure off the BCG until the BCG moves back onto the buffer during its cycle. Again During Normal Operation The Buffer Comes Into Contact With BCG - But DOES NOT Apply Pressure!

 

 

Shot 4 More Magazines Through The Gun At Only 1.5 Reloads Per Gas Fill.

 

Fawkin Gun Just Doesn't Quit!

 

Gas Efficiency is WA Design At Best But Still Shooting - UnFugginBeleivable!!

 

 

Total Magazines Expended Today = 10

 

Total Issues / Incidents Encountered = 1 Broken Lower Receiver

 

Total Bolt Locking Back After Last BB = 10

 

Total Magazine Count Expended = 336

 

Total Round Count = 10,752

 

 

 

Email To KJW:

 

Clare,

 

My KJW M4 Lower Receiver has Broken!

 

The Buffer Pin has broken inside the lower body and I am afraid I need a New Lower Body!

 

Here are detailed pictures of the gun failure.

 

Please Advise On What I need to do!

 

Thank You

-Raven1

[wdahm519]

Wow, when t_hum text'd me this I had no idea it was this bad. That really is not good to hear!! Please, please keep us updated on what KJW does.

 

I'm glad to hear she doesn't quit though

[BrooklynBorn]

Holy sweet mutha-effin JESUS.

 

So despite that issue, it still WORKS?!?!?! AMazing. Must have for me.

 

Also, why the hell does that outer on Intrudershop cost half the price of the gun?

[sacairsoftsn00py]

How about making a shorter piston than the stock one? By having a shorter piston, the gas ends up having more room to vent out off which reduces the pressure built up. It may or may not reduce the blowback, but if it will increase the gun's durability...why not?

 

KSC MP7's have a longer piston than the KWA MP7's. This is how I came up with the idea of possibly doing the same to a KJ M4.

 

Also, do note that Raven1 is in Arizona. He has put his gun through almost twice as much abuse as the gun is meant to be used. Still, it would be good to know that should anything else go wrong, KJW will provide good customer support as they have in the past.

 

I am still awaiting for their response with regard to the elastic band replacement i requested.

[BrooklynBorn]

How about making a shorter piston than the stock one? By having a shorter piston, the gas ends up having more room to vent out off which reduces the pressure built up. It may or may not reduce the blowback, but if it will increase the gun's durability...why not?

 

KSC MP7's have a longer piston than the KWA MP7's. This is how I came up with the idea of possibly doing the same to a KJ M4.

 

Also, do note that Raven1 is in Arizona. He has put his gun through almost twice as much abuse as the gun is meant to be used. Still, it would be good to know that should anything else go wrong, KJW will provide good customer support as they have in the past.

 

I am still awaiting for their response with regard to the elastic band replacement i requested.

 

Would it be possible to use ANY rubber band? I mean, it's just a piece of elastic

[wdahm519]

As long as its the same length, yes.

[sacairsoftsn00py]

I would rather have an original part.

 

The original band is not really elastic. Its more plastic than elastic. Plastic=harder than rubber. Retains its shape. The band was there to absorb some shock without collapsing.

 

Personally, I do not want the nozzle slamming back into place because of a rubber band's elastic properly. It already does that with the spring.

 

What the band does is that it keeps the nozzle from being left to the front. That also means it keeps the spring that's attached to it from over stretching (which would result in the spring snapping- meaning more broken parts to order from KJ).

 

The plastic band allows for the mechanism to glide through it without binding/gripping on it.

 

If only we can find the company that makes them (or somewhere that sells the same spec/material band).

[Robinio]

Hm, is this the first major problem?

 

How cold was it when it broke?

[sacairsoftsn00py]

He had been testing his gun under extreme conditions (around 110-115 degrees) in the past. That means the PSI from propane has almost doubled from what the pressure is at 70 degrees.

 

With that said, his lower receiver broke at about 85 degrees.

 

You should look up Raven1's posts as his accounts are well documented. You will see how much he has pushed the gun.

 

The only persistent problems that multiple people have suffered are the broken nylon bands for the bolt carrier group. Next to that would probably be the front receiver tab (that probably result from people letting the upper receiver assembly dangle from the lower receiver or over torquing the barrel nut assembly.

 

The broken lower receiver is a first.

 

Even after those broken parts, the gun still shoots. Not as efficiently as before....but it shoots.

 

------------------

 

I heard from KJW back.

 

Total cost for 5 elastic bands and 2 hop buckings come to $44.50

 

I am guessing the buckings cost 5-10 bucks a piece? I'd just rather have them and not worry about it later.

[wotty33]

He had been testing his gun under extreme conditions (around 110-115 degrees) in the past. That means the PSI from propane has almost doubled from what the pressure is at 70 degrees.

 

With that said, his lower receiver broke at about 85 degrees.

 

You should look up Raven1's posts as his accounts are well documented. You will see how much he has pushed the gun.

 

The only persistent problems that multiple people have suffered are the broken nylon bands for the bolt carrier group. Next to that would probably be the front receiver tab (that probably result from people letting the upper receiver assembly dangle from the lower receiver or over torquing the barrel nut assembly.

 

The broken lower receiver is a first.

 

Even after those broken parts, the gun still shoots. Not as efficiently as before....but it shoots.

 

------------------

 

I heard from KJW back.

 

Total cost for 5 elastic bands and 2 hop buckings come to $44.50

 

I am guessing the buckings cost 5-10 bucks a piece? I'd just rather have them and not worry about it later.

 

Hey sacairsoftsn00py, do you have an email contact address for ordering those? i'm guessing a pre-order is a pretty sound investment

 

cheers

Edited November 9, 2009 by wotty33