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KJW M4

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T-hum, when i opened up my m4 to put grease on the piston o-ring i noticed that the lower receiver has the crack in front of the thing that holds the buffer in. Would that affect the full-auto in anyway? I also found that now the weather is cold I had to loosen the sling mount that goes over the buffer tube as it's tight enough to pinch the tube out of shape just enough to stop the buffer going full forward on occasion.

 

I cleaned the piston and re-greased with AEG piston head grease and the problem is still the same.

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Nice setup!! I'm digging the UBR! I hope you did not go the 'difficult' route installing it as I have.

 

How did you install it?

 

Thanks.

 

ETA: Which version MOE grip did you use? Was it a simple plug and play install? Thanks.

 

For the ubr install the credit goes to Rookie Abs

 

- Beefed up the kjw brass inner buffer tube with duct tape so that the ubr slides on

- Drill & and tap a hole in the kjw buffer tube end cap

- Screw in the ubr

 

I used a real MOE grip meant for a real gun. It was simple plug and play, but you have to use the original kjw screw

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The crack you described happens from the bolt carriers being too short. Dont know why KJW hasnt addressed this yet. The carrier extension I make is designed to prevent what happened to you. It could be contributing to the full auto problem, certainly. Does the detent protrude higher than it should now? Could it be rubbing?

 

If your buffer is rubbing at any point along its travel thats also a cause for concern. Should be smooth as butter.

Edited by t_hum

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Sadly I can't tell because i didn't pay enough attention to how it looked before it cracked :( However, when i point the m4 upwards and rack the charging handle, the bolt moves slow enough that it doesn't return to battery some of the time. I'm not sure if this is because it's colder weather now or if it's the retaining peice's fault. Subjectively it feels like the bolt is moving slower when I let it go as well. Could cold temperature make it do that?

 

EDIT - just took a better look and it could be resting higher than normal, maybe by half a millimeter or so?

Edited by tome

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not when doing the operations manually.

 

Try to get the buffer moving smoothly first. Lightly lube the buffer and tube. After that check movement. Hopefully the inner brass buffer tube isnt too crimped from the sling mount you had on there.

 

If the carrier assembly doesnt move smoothly at that point Id do a trial run without the buffer detent installed to see if that makes a difference. Can you post a pic of the buffer detent and its surrounding area?

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OK took a pic.

 

I've loosened the sling mount enough now that when the buffer is in the tube without the spring it will travel the full way up and down when I tip the tube up and down. That should be smooth enough right? It slows down a tiny bit at the crimped point but will keep on moving.

 

I'll test the carrier movement now.

post-7759-12875965948121_thumb.jpg

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ok, i've put it back together without the detent and the carrier still doesn't always return to front completely, requiring a little push of the forward assist to seat it. I noticed that the buffer is a really snug fit with the buffer, enough to be slowed down by the air needing to escape between it and the tube when i dropped the buffer in without the spring. Is that normal?

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ok, sorted out the problem with the buffer moving slowly. I figured it wasn't supposed to have an almost airtight fit with the buffer tube so i filed around the head of the buffer and now the buffer moves smoothly and quickly.

 

Unfortunately.... it still stops randomly in full auto.....the investigation continues

 

edit: not entirely sure why the buffer had such a tight fit in the first place. Might be the carrier hitting the buffer and deforming it outwards enough to get it to form a semi-seal :S

Edited by tome

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I would love to mod mine, I'm a little stuc though. I'm nog that handy and I haven't got the needed tools.

I want to put on a CTR Stock, that's a no go though.. (with the tools I got etc.)

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Both sytles and for both the WA and KJW platform.

 

This will be a simultaneous release. 90% of the parts are the same. The store will be set up to allow you to buy the following:

 

1. Complete KJW guts

2. Complete WA guts

3. Stanag shells

4. Pmag shells

5. Top portion of magazine for KJW

6. Top portion of magazine for WA

 

So you could technically buy and then convert both style and platform.

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That sounds pretty much perfect t_hum..

Would there be any issues sending them to Hong Kong or the UK (assuming I don't have membership for the airsofting stuff over in the UK)?

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Would there be any issues sending them to Hong Kong or the UK (assuming I don't have membership for the airsofting stuff over in the UK)?

 

The only restrictions in the UK are on importing fully assembled guns, everything else is fine.

 

t_hum, are these made using real PMAG and STANAG shells?

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The shells start out as rs shells but are the modified in several areas. Round count will be as close to 50 as possible. I have some numbers somewhere for reservoir size. I'll have to dig them up.

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