Is Mopar making gun parts now? <--- said as atctimmy laughs at his own joke.
ETA: I know I'm a goober. You don't need to tell me.
It worked. I dunno what happened but it worked. Per your suggestions, I am waiting for the receiver vice block and barrel nut assembly I ordered from Brownells. I left the barrel in the vice. When I was out in the shop doing whatever I had given it a try, a couple of different times. Thursday evening I took another crack at the barrel nut and off it spun. I have no clue what happened it just came off like it had never been stuck. Checked the treads there was no sign of galling, loctite or anything else. So I am clueless what the hell happened but it is off.
I want to thank each and every one of you for your input and assistance. I especially want to say thanks for keeping this on topic without all the negative carp about Bushmaster that is all to common on other boards. ON AR15 they'd have buried my OP in anti Bushmaster slams. For myself it looks like I have to retract my list of BushMaster complaints. Barring this weird bit of melodrama mine has served me well and gone bang each time I squeezed the trigger. Again thank you for sharing your knowledge and expertise with insightful well thought out posts.You are true gentlemen thank you for the help.
No one should feel embarrassed about any firearm they own. If he came here first asking for advice, then went out and spent more on a Bushmaster, that's a different story. 5 Years ago, we didn't have nearly as many options, consumers weren't as educated and those that were available were harder to come by. So, though Bushmaster had the same practices as they do now, more people owned them and many tuned them to fit their requirements.
For the over-gassed comments… It's not all Bushmasters, but many are. They are not all consistent with their gas port size. One may be in spec (kind of, I'm not getting into that), then another might be .075 or even larger for a 16" barrel. Depending on the barrel steel, there's a chance it may erode sooner or faster and open up. .063 is the size that Colt, Noveske, LMT, Bravo Company, Daniel Defense and others on par use for 14.5" and 16" carbine gassed barrels. Anything larger is is potentially going to be over gassed with NATO ammo. Bushmaster, DPMS, Olympic and others regularly use ports much larger, many use .070, which is tolerable only with 223 pressure ammo, but will likely be overgassed with NATO and will only get worse with wear. And, contrary to popular belief, there is no fix for this. A heavier buffer is a bandaid, but NOT a fix.
It's no big secret Bushmaster sets their rifles up for civilians shooting 223 ammo. It's also no secret that if you take 10 Bushmasters, there's a very good chance at least a few will need their "5.56" chamber reamed, as it will very likely be closer to 223. I know of an entire fleet for some contractors in Iraq that had to be reamed. We're talking well over 100 rifles new from the factory.
It's also no secret that they ship with carbine buffers. This is an easy fix, but does everyone know to fix this? What do they do when they get a deal on 855 and run a case through their Bushmaster with a carbine buffer, even if it has the proper gas port size of .063? Eventually, this will lead to a problem. Many guys will buy what they find at the shop them go about their business. This is fine, but when they run NATO ammo in their Bushmaster with a claimed 5.56 chamber, slightly larger gas port, semi carrier and carbine buffer, they will likely experience problems at some point.
I'm not bashing Bushmaster in any way, but it would be nice if they got their stuff squared away. It would be even nicer if consumers educated themselves enough on the differences so they understood the negatives to buying one, even if it's for dirt shooting. People do not know and that's the problem. It's not the rifle they own, it's that they don't know what is necessary for that rifle to perform at it's best.
A guy I know, and a couple of you may as well, is a full time LE distributor for a couple manufacturers, Bushmaster being one of them. EVERY single Bushmaster that goes out of his shop to a department is reamed and the carrier and buffer are upgraded. The staking is checked or corrected (often corrected). He deals with hundreds of these rifles. As many problems as he's seen, he's decided to do something about it up front.
The sad thing is, this is easily corrected by the shooter, but most will not take the time to understand what is needed.