Pulled the 243 barrel from my Axis when I did my 450 Bushmaster build. There's soooo much crap in the barrel threads that I can't get the nut to come off! I clamped it in my vise and used my nut wrench getting the nut to where it's about an 8th of an inch past the chamber but now it won't budge either way! I don't want to split the nut if I don't have to. Any ideas on how to go about getting it off. Would heating the nut help?