Help need - stuck barrel nut on an ar15

Is there anyone in the taranaki region that is able to give me a hand with the above?

I am wanting to change out my spikes tactical SAR3 rail and after a couple of weeks I am admitting defeat and asking for help.

I cannot for the life of me get the barrel nut off - I started with treating it with wd40 (5 days) , I have been applying kroil every 24 hrs (4 days), I have tried heat, I have tried cold, I have tried talking nicely to it and I have yelled profanities at it.

I have got to the point now where my ar wrench slipped and damaged the nut (which is where the profinities came in). I dont want to damage it any further as it is a proprietary nut.

Any advice or assistance is welcome.

Cheers

Maybe a strap wrench and a half inch bar?

+1 for the strap wrench and bar, heat it again too.

Thanks guys I will definitely give that a go tomorrow

Thanks guys - alot of heat, strap wrench and a ton of elbow grease and she finally gave way!