Using JB Weld , or similar as filler on Aluminum

redshooter

redshooter

CGN Ultra frequent flyer
Rating - 100%
115   0   0
Location
Central Ontario
Good day gents!

I still haven't changed my AR Upper, and once again I'm making a related inquiry. I have an HBAR upper on a standard lower, the bushing works, but not as well as I'd like, pain in the a$$ really. From my research I've found that M4 Ramps with a Rifle extension, MAY be ok, but not a good idea in principle, so I'm not going there. The rifle ramps in the extension may be extended with a diamond file/die grinder, but when I inquired about if anyone knew if the extension was hardened all the way through, or just surface hardened I got no reply, until I can find out that tidbit no grinding.

I had a stupid idea/brain wave the other day why not fill in the ramps with JB Weld. Will it work, and if so what would I need to do to prep the surface etc.

For those who will have the urge to say just get a rifle receiver, yes I'd prefer one, but I live from pay cheque to pay cheque, funny how an extra $50 - $100 can put something just out of reach. Inexpensive receivers with M4 ramps are a dime a dozen, receivers with rifle ramps are few and far between to begin with...I've yet to find one for $100 on sale, M4's, every month, or so.
 
I am not an ar expert, nor am I a money expert. I do have some advice though. Gunsmithing is not best done on the cheap. If you screw up you will have a very expensive repair at best/paperweight at worst situation on your hands. I would definitely selling or swapping either your upper or lower.

On a more personal note, and I mean no disrespect as we have all been there, if 50-100 dollers can make the difference in paying your bills maybe stick to a good bolt 22 until you have improved your situation.

Good luck sorting out your rifle. Let us know how it goes.
 
I to ran into this feed ramp mismatch phenomenon when I changed out the upper on a CQ311 (I wanted an adjustable rear sight). I was kind of p..sed that the smith that changed it out for me didn't point out the mismatch to begin with. The rifle ran just fine as is but I to did try the JB Weld idea. It seemed to stay in place but I don't think it really accomplished anything.

Just leave it be unless you encounter issues.

M
 
new210/22 said:
On a more personal note, and I mean no disrespect as we have all been there, if 50-100 dollers can make the difference in paying your bills maybe stick to a good bolt 22 until you have improved your situation.
Click to expand...

The end is near! Well maybe not that close, I suppose I could wait, die, and not enjoy the time I had. Saving isn't really practical when you're a seasonal worker. When you're pretty much at the top of the local blue collar pay scale my situation is only going to improve by moving. That's not going to happen for the moment for personal reasons. If I can get pretty much the same thing for $100, and two small dabs of JB Weld and an hour of my time, why spend money that could be needed for car repairs, or in the case of this month easing my old dog's suffering? Something always comes up when you are just squeaking by...

gnmontey said:
Just leave it be unless you encounter issues.

M
Click to expand...

I suppose I could assemble it and use a few dummy rounds to see if it's going to cause me grief.


I was considering seeing if I could do a trade, and swap uppers with someone looking to build a C7/ M-16A2 clone on the EE, but if I do my part, and feed it good ammo, the barrel is sub moa. It seems foolish to give that up for something that may not shoot as well.
 
Last edited:
Might as well try it.

JB so called Weld is just crappy epoxy (ok, not THE crappiest, but...) with metal powder added in. If you want it to stick in place, clean and oil free is a good place to start.
Will it stay put? Time will tell.
 
The barrel extension is case hardened, so while grinding the feed ramps to match the receiver could hypothetically get you beneath the 'hardening', it's not going to be a problem, because the BE is still 'hard' all the way through, it just gets less hard towards the middle (surface will be ~55RC, then as you move away from the surface, it may get down to 40-45RC, still harder that the barrel which will be in the 28-32RC range). The bullets are not going to wear your extension away nor will your BE fail.

My opinion: just install the rifle extension in the M4 upper, and if it feeds fine, call it a day. If it doesn't, dremel the feed ramps onto the BE while it's in the upper. I prefer a carbide burr, but a rotary stone will work too.

While I have 'fixed' a great many things with JB Weld, and they have held solidly, Murphy dictates that the glob of JB Weld you put on the receiver will become dislodged at an inopportune moment.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom