plastic tabs

[gundown]

is there any good easy way to fix plastic tab on an m4

[guard-sniper87]

Re: plastic tabs

nope,

replace the plastic body with a metal body,

or buy another plastic upper reciever

[Bachelarius]

Re: plastic tabs

Arise, dead thread! Sorry for necro, but I've been working on repairing them for the last few days.

There are two possible fixes floating around actually, rebuild the tabs or improve on the locking mechanism.

I think that the latter solution is the better one and is outlined fantastically here. Pros: Solid bond, which will not break ever again, unless you use crap glue. Con: you lose the ability to break the reciever in half without removing the front pin, i.e. you have to take both pins out and slide the receivers apart.

Sadly, I didn't have any 1" pipe, so I went for the 'rebuild tabs' option.

Basically, the way I did it was first to cut off the remainder of the broken tab up to the slopey bit which centres the upper receiver in the lower receiver.
I then drew the shape of the tab on a piece of plastic card, eg credit card. I then built up the thickness of the tab to as thick as I could, glueing the sheets together with araldite.

Right, tab rebuilt. In order to attach it I cut up a coke can and stuck a long sheet inside the receiver, again with araldite. I ran it under the rubber sheet/spacer, that's just inside the receiver. Then I used a heated knife to cut a small slit on the outside of the receiver, just under the slopey bit, so that it is flush with the top of the tab and made it about 10mm deep. Here I attached another sheet of can metal into the groove (again, smothered with araldite) and melted the plastic of the slopey bit back over the top of it.

Got one tab done so far, one more to do, then all I need to do now is drill the holes for the pin to go through and the job is done. I honestly didn't expect this to work, but it seems as solid as the original tabs were and because I am able to make the tabs a bit thicker than the originals, there is a tighter fit and less chance for them to break off mid-skirm.

Anyway, pics attached, apologies for the somewhat shoddy looking workmanship, it's ugly but it really does work.


[Edit] Or just use a zip tie to hold the receivers together, haha [/Edit]