Help removing muzzle brake...

If all else fails, you can try this trick [assuming you have access to a long freezer]
I had to do this to one of my centerfire rifles to get the barrel out of the receiver:

Throw everything in the freezer overnight, and get it all as cold as possible.

Later - Use a heat-gun again, only on the brake, working the heat around the whole circumference.. 

By doing this, [cooling and heating] you'll be 'shrinking' the metals, then 'expanding' the metal..
It definitely works.

 

Sam -

wrap a cold rag around the barrel then heat the muzzle break all the way around as fast as you can, will work better if you can keep pressure on it but you have to be fast because the heat will transfer to the barrel & your screwed again. but I think you should be pretty close to having it off Best of luck

If you’re impatient & don’t have a deep freezer there’s always keyboard cleaner spray. Don’t freeze it inside & breath that. And I’d also try PB Blaster or WD40, Slick 50 One, let it soak. Work it back on first as if it’s stuck at a certain point it may slip off way easier once fully on, indexed free spinning & find a rotation where it slides off unhindered, if there is a spot. 

Anything that requires a hammer on precision equipment gets me questioning my actions. I don’t have proper equipment to break free barrels, brakes, shotgun tube fed magazines, etc. & it can be a real SOB to impossible without it. 

Grub screws? Backed out completely? A burr?

JamesD. just brought up an Amazing trick! *compressed air / keyboard spray*

Obviously, it just comes out as air - when it is right-side-up... 
Flip the can up-side-down, and it will shoot out liquid - Freezing Cold Liquid!

I used to use that method to help freeze metal - then heat - to pop out dents [at my bodyshops]

Again - That definitely works!

Thanks DD, in safety’s sake, wear gloves & do not spray that on yourself. It evaporates very quick, actually boils away. It’s not liquid Nitrogen cold, you can’t freeze & have it crack super easy. Probably-180-200*F my guess. 

When heating you want to heat evenly but keep it below 300*F. So an easier way to tell is a light coat of oil wiped off. You start seeing that smoke you’re there. Or if a drop of water hits, sizzles & beads off, it’s on the too hot side. 

None of this is going to hurt anything in these circumstances. I wouldn’t do it to a highly prized blued area but the brake, hmm.

What other aerosols readily available are helpful here? Keyboard cleaner use to be available almost anywhere but Staples or some electronic store now. 

That idea brought the cryogenic barrel treatment to mind. All I know is it is supposed to rearrange molecular structure & benefit accuracy in harmonics I guess. I don’t know if it helps to shorten gaps of cold bore & hot shots from stringing. Someone here knows but it ain’t me. That’s why I’m here. To learn.

Watching this with interest as I have the exact same problem, also with an RX2. Tried the block of wood, and the heat, and the rubber strap oil filter wrench, no luck.

Please let us know what magic combination gets that brake off. 

Might just have to get used to it hanging out there. If someone whacked it on with a mallet, you’ve got a metal-on-metal press fit