As noted, I sell the barrels when they are taken off.

Good enough barrels but not what I am after.

I have a NSS action wrench , pipe wrench (loosely done as noted by RH) and it came off fine.

Heat may help but that was based on a locktite on the threads. We are accuracy informed that there is nothing but polishing residue, heat might still help but heat is directed at locktite to turn it to ooze.

I had no problems, but the nut came off pretty easy even with an 12 inch pipe wrench.

I had a faceted nut that took the long barrel nut wrench, a breaker bar on it and my sadly too much weight to break loose.

You get one of those hard ones off by cutting most likely.