Ok, I got this nut super hot, smoke was billowing out, locite was liquid on the barrel, I was wrench left handed in a vise and it still didn't budge. What the hell?
Are they just super tight and I need a bigger vise and wench?

HOLY CRAP!
So I went back at it after dinner. I'm not little. I bench 250 for reps. I curb 50 lbs per 10 reps. I squat an ass load. I weight 230, no one thinks I'm small.

Anyway, I'm not little.

I heated this thing up again after din din, like blue orange.

I stood on it in the garage and lifted with my legs and I got it to budge. HA! STEYR!

I heated again.

Pressed it out again.

Heated again.

I pressed it again and got it off.

No shit I felt like I was lifting like 300 lbs. Jesus, Steyr, it doesn't need to be that tight. And 1/2x28" threads next time.

BTW Love the AUG. Getting another.

Now I can run my thread on canz.

I had a similar experience with a SCAR flash hider.

Similar H/W @  6'2", 220 lbs.

Heated up bright orange, and with a 3ft cheater bar took a quarter of my body weight to get it to break loose.

Ended up having to make some custom blocks for my vice to grab the tapered barrel of the SCAR.

http://www.ar15.com/forums/t_6_24/423112_SCAR_16_10_Barrel_Flash_Hider_Removal.html

My bench vice actually broke a week later when working on the next project.  Started to tighten the vice down on I beleive a lawnmover part and the main lag screw in the vice just snapped in half.

I had that vice for probably a decade with tons of projects under its belt.   Getting a SCAR Hider off ended up killing it.

I wonder what these folks use for threadlocker sometimes.

Wait,what?
Tighten the nut to loosen it?

But it definitely does need to be heated, correct?
Thanks Pete.

The checknut is tightened against the flash hider. The way it is "tightened" against the flash hider is done by rotating in the "loosening" direction.
So, to get the checknut off of flash hider, you have to rotate it in the "tightening" direction.

Just got my Ratworx suppressor, and need to remove the FH. If I recall. Correctly it LH threaded. What wrenches are you using? My standard craftsman wrenches have head flats that are too thick to grip the FH and jam nut.

You have 3 choices:
Grind down the wrenches you have so they fit.
Buy "tappet" wrenches.
Send your barrel to Pete, he has a fixture and can get even the most stubborn ones off.



Craftsman tappet wrench on A3 flash hider:



MAC tappet wrench on A3 flash hider:

I used a set of shitty thin wrenches I had on hand:

http://www.amazon.com/Grip-Thin-Wrench-Set-MM/dp/B001PTF9MY/ref=sr_1_2?s=hi&ie=UTF8&qid=1414587943&sr=1-2&keywords=Thin+wrench+set

And a Hammerhead that's thin enough to work and has a cut out for a 1/2" ratchet/breaker bar.

http://www.amazon.com/Hammerhead-Rifle-Tool-wrench-medium/dp/B0096EG41U





 

I did my M1 barrel last night, the check nut and flash hider on the new style tulip was a perfect fit on a Tapco AR Armoer's wrench.  Propane torch, elbow grease.   Go slow.    Now I have an AAC flash hider so I can use my 7.62SDN6 and eventually my Saker when I get the 51 tooth adapter.