I also tried the heat shrink wrap mod but it did not do anything for me.

thank you! Happy I m not alone...
Will try this

You shouldn't even need anti-rotation pins. If you put put the pin in correctly, the full auto sear spring should hold it down. If you look at the hammer spring, there is a notch on one side. Make sure the pin is put in so that the end of the "V" shape spring sits on the notch. I'll do a instructional video if you need it, let me know.

Sharing the photo, hope you guys like it.

I love KJW M4 Very relliable mine still in good condition.

Anyone know how to change the hop up rubber? I don't like the stock one.

Dial the hop up back to original position first.

Remove the flash hider (the thread is counter-clockwise, so turn it clockwise to loosen it, and some models have a small hex screw at the bottom of flash hider), front sight (punch out two pins), hand guard, gas tube and get to the delta ring. Unscrew it (clockwise thread, so turn it counter-clockwise) until you get the entire front barrel assembly out. The inner tube should fall right out. Get ready to catch it, don't just let it fall right to the floor.

The hop up rubber is sandwiched by 2 metal pieces and secured with a metal ring/tube thingy. Pull that metal ring/tube (towards the front) and the 2 metal hop up piece will just come apart.

You can access the hop up rubber now. The notch on the inner tube matches to the nib of the hop up rubber.

Assembly is reverse of the procedure. You may notice there are two small grooves on the inner tube, one near the hop up and one near the front of the inner tube. I am not exactly sure what they are for but I put two small o-rings on there which help to stable the inner tube. Or two revolutions of scotch tape will do the same job. You will feel slight tightness when you reinsert the inner tube if you did this mod. I did this cause when I changed to 363mm inner tube, I noticed slight play hence I did the mod.

Hope this helps.

Cheers

I only needed to figure out how to get the brass ring off the hop up; I thought it had to screw off. Thanks.

Gamed the gun for a full day yesterday with the new NPAS and ACOG. I am in love with it!! Everybody at the game was afraid of it because it was so loud.
Thanks to Amos for the NPAS! Being able to adjust the velocity was great, especially when the temperature increased in the afternoon.
The ACOG was great. Except after a while the screws in the bottom of the mounting plate holding the scope to the plate became loose from the recoil. The RAS also started to come loose too. But overall the gun held up great!

Glad you're enjoying the gun :)

Got mine today, with blue RA tech hop up bucking. Hop Up is not bitting enuff on the BB, is there a fix out there? I saw the screw fix top down from the top railing posted by HKp30 but I don t feel skilled enuff to venture myself. Anyone has a easier fix?

Thanks

Anyone think this this barrel would fit a KJW M4?
http://shop.ehobbyasia.com/accessori...er-barrel.html

Also are the Falcon hop up rubbers any good?
http://shop.ehobbyasia.com/upgrade-p...60-degree.html

Yea, the blue hop-up rubber don't work so good for some reason. You can do the screw trick, but the easier way is to put one or two pieces of heat-shrink on the hop-up arm.

I don't remember well, who here does have the rubber band in stock? I'd like to get myself 2 or 3 just in case !

Get bicycle innertube instead. Much cheaper, I can't remember the size though... Amos what size did you send me?