G&G R4 Inner Barrel Removal

[Darklen]

Ok, this should be easy, but...

All the G&G R4's I worked on, hell all the armalite AEG's I've worked on, the inner barrel & hopup virtually fell out on their own. This one, I've pounded on with a punch and yanked with visegrips for over an hour and managed to get it about half way out. And, no, it's not bent. It's stuck, and how. It won't even twist in the outer barrel. This one is one of the newer versions, with the non-reinforced mechbox and the wonky mag release you have to press in all the way and unscrew the actual mag latch as there is no screw on the button, just a rivet.

Am I missing something here? Are these glued in or something? Or did this client just get a "unique" gun? Unless I'm missing something, next step is a heat gun, after that, more brute force I guess.

[Darklen]

Well, after judicious use of both a heat gun and a couple of visegrips, the inner barrel came out. Using a bore brush, I managed to clean out about 1/4 oz of some type of resin/laquer/spooge/whateverthehellitis that was clinging to the inside of the outer barrel. I went to install a Systema M16 barrel in it to check of fit and, nope, no go. The out barrel is not bent either. It only goes in about 4 inches from the muzzle or the "breach".

Anyone have any idea on how to ream/sand the inside of an M4 outer barrel?

[wey ferro]

just buy an outer barrel im sure you can get them for around 50.
or take it to a machine shop.

[Darklen]

Unfortunately, my client is already looking at a $200-300 repair bill, just in parts. Understandably, I'm trying to keep his costs down.

[wey ferro]

a dremel bit on some sort of extention?
thats gonna bump hours up alot though.

[Dracheous]

Go get a mutli-bore rifle and shotgun cleaning kit and use the brass brush to clear the laquer out.



Was this a NEW rifle when you opened it? If not then I REALLY do think that someone tried to stabalize their inner barrel by glueing it in place. Why can't anyone just use a little tape or run by the hardware store and buy a 0.20 O-ring!?


I doubt that was done by the factory, but hey! stranger things have happened no?

[Darklen]

Client claims he got it new from a retailer a while ago, it's far from in new condition now. All the other damage was user caused, but he claims he never touched the inner barrel. Only reason I pulled it was to install a new hopup chamber.


I'll try the bore brush and some solvent of some kind. I;ve worked on 3 G&G M4's and 2 M16's and not seen this, but all the others were older models, with the reinforced gearbox.

[Dracheous]

Hmm, I don't know of any gun having any "good" reason to glue the inner barrel in place. The only ones I've seen/dealt with that were glued were glued their by the previous owners.

One thing crossed my mind, ask him if someone before had tried to use any kind of glue to tighten up the hop-up assembly. Sounds stupid and I'll have a couple local guys either laughing or slapping me in the back of the head here, but I did use a similar method to fix a pistol here. But if there are EXCESSIVE ammounts there its probably not this.

I read somewhere of someone fixing their hop up to get a few games out of it before they got a replacement and that was basically setting the wheels where it fired and then put some liquid glue. IF they used a liquid cement that you get in any hobby store it WILL dry to look kind of like a laquer and will brown after time. Which is why hobby stores always have lots of this stuff, experiences hobbiest in model construction won't use it for anything more than making scenery. Anyway, back to the point was if they tried to apply this and it was dropped in using the eye dropper its possible that the glue just seeped into the inner barrel.


I did something similar to fix a hop up on a KJW Para. The hopup is going to die, maybe get another 100 rounds out of it and its now more of a fixed hop up. I used the glue with some fine dust to create a small "wedge" to push the hop up rubber down so that it actually retains the round since it has been wore down. Before I did this when the gun was pointed down the BB would just roll out. Now range wise its not the best, but since its not possible to really adjust it, its the best its gonna be for now. Anyway, its just a thought on MAYBE how the glue got there. But it doesn't make sense for G&G to glue the barrel in place as it wouldn't really be centered. It'd make more sense for them to send the guns out with some kind of ring around the barrel to stablize it.


Anyway, back to being another hampster in the wheel for me. Oh ASC, the escape gateway from work. . .

[Lord_Jeremiah]

You see, the reason the hop up is busted off, is because I was attempting to get the barrel off. I couldn't even do that, as the barrel was on WAAAY too tight for me to pull off, and resulted in the hopup breaking off the barrel.

Now I'm starting to wonder what happened to this gun before it left rangers, especially with you mentioning guns should never be shipped with a connected battery...

Bob, you don't think you can get a macro picture of down the barrel do you? I'd like to see how bad this looks.

[Darklen]

I've used a softish bore brush to clear out the loose junk already, so there's really nothing to see. I've shon a laser pointer down the inside of the outer barrel and there's no bends worth noting. All I can think of that would be causing the problem now is more of this goop that came out with the inner barrel. I'm going to try progressively stronger solvents to clean it out until I can fit a new inner barrel in properly.