take a close look at the threads. If you see red thread locker on it, you will need lots of heat to remove it.

^^^^^ This. Can't stress it enough. The tool is cheap. Get one.

I've used mine once and it is well worth the price!

Bringing this up, dont want to start a new one.

I want to put a shorter barrel on my KA M4, but the nut wont move at all. I ordered a delta ring wrench, but from this thread, i think it won't move anyway..

I'll have to cut it :banghead:
I don't thing the delta ring will be hard to remove, but when it come to the barrel nut, i worried about cutting the threads on the receiver. Any tip to avoid damaging the receiver?

Use a cut off wheel and go carefully. If you cut most of the way through until you start to see the threads before you hit the receiver ones, you can get a flat screw driver in the slot you cut and twist. It should snap the barrel nut open. I have done that on a few with no damage to the receiver

I put my upper into a vice, then used my KA wrench took a bit to get it loose but afterwards it came off no problem, it looks like they glue these fuckers on

A quality AR15 armorer's wrench will open the KA barrel nut at around 45ft-lbs.

Thank you! I'm trying to remove my barrel before odering the new one from you =)

Huh, that's right in the range of real steel AR-15s.

Without a proper picatinny clamp and/or vise, I'm not sure how one would go about it without damaging the receiver. I don't blame people for cutting them off.

I dont want to damage my receiver. What's the best way to put the gun in the vice? Only with upper receiver or the whole gun? Do you have any tips how to do that properly ?

I would normally use an AR-15 upper receiver block, but I have a GBBR so I'm not quite sure how closely the inner of AEG uppers follow the RS spec. Brownells has upper receiver clamps which rely on the outside of the receiver instead of the inside. Clamp the receiver into it, put the gun in the vice, work slowly. You can wail on an RS receiver, but on a pot metal AEG receiver I'd err on the side of caution and use heat on the nut if required. If you really don't feel like the investment, you can make your own blocks... but ensure you're accurate and on point. Having a loose vise block is an entire level of frustration.

Don't ever do it with your receivers linked, ever. Even on a real AR the pivot pin points aren't meant to take that moment/torque (Note the reinforcement from A1 to A2 receivers) and on an AEG, you WILL snap the pivot points.

I already feel dicey doing it with an actual AR-15 upper receiver, though I suspect it's more due to the fact that aluminum is much lighter than pot metal despite its higher strength.

dremel it!
 

I just spent a couple of hours attempting to remove this by heating the nut, and cooling the body, and this thing will not budge. I took it to a buddy that has a machine shop, and when we applied enough pressure, the body started to warp, so we stopped...

Then, it took me less than 10 minutes to dremel the nut off the body, and then 20 minutes to put the new RIS front end on it, and re-assemble the whole gun!

Lesson learned KA! Lesson learned!

Just dremel it!

S