Nightmare barrel nut!!! - Aero Precision M5E1 20in .308 Barrel Complete Upper Receiver with Flash Hider

This is a bad dream! The barrel nut won’t come undone, as if were JB weld in the threads. Plus, this is a enhanced M5E1, its upper only compatible with Aero Precision hand guards. Now I can’t take the barrel off to put on a new M5 upper for the Atlas hand guard. Reminder, this is a discontinued keymod M5E1 upper. I wanted upgrade to M-lok, now got to buy the whole kit(barrel included) to get my .308 up and running. Moral of story: BE CAREFUL OF YOU WHAT BUY! This is on Aero Precision not Optics Planet. It’s my fault for not understanding AR10 is a very non-standard platform, it’s a hot mess! M4/M5 enhanced upper is and was a terrible idea.