pistol seems to not be straight on with the camera, but that rod is deflecting too much. the barrel and suppressor should be mounted outside of the slide to ensure that that assembly is square for the interface between them. that is the important metric to determine, the barrel when in the slide is largely inconsequential during firing. the one exception to this is fixed suppressors like old school ones for the Beretta which are attached to the frame or slide rather than the barrel.
I'm once again trying to do some home gunsmithing like an idiot and I need a consultation before I do something potentially retarded.
A couple years ago I built an AR-15 with an Aero M4E1 receiver. The barrel nut is somewhat different from normal. Now when I put this barrel nut in, I put some aeroshell in on the threads, but I had no idea what I was doing used way too much.
Fast forward to now and I can't get the barrel nut off. Like, at all. I'm guessing (but not sure) that it's related to using too much aeroshell. So my current theory is, heat gun plus a foot long piece of steel pipe on my wrench for extra leverage.
Good idea or worst idea?
the BEV block should work for disassembly as long as you didn't mongo the barrel nut on there. too much aeroshell makes a mess, it generally doesn't sieze up unless the grease somehow became contaminated during application (one dumbass used loctite on a barrel nut i had to cut off years back, what a pain).
i use a specialized vise jaw set profiled specifically for the M16A2 (i have both an upper and lower set, including a set of Colt vise jaws set for a long tapered AR-15 barrel) from Bushmaster back in the day for most of my assembly work, however i've also used the BEV block, various clamshell style ones, that Sabre Defence two-piece stainless one that's a pain in the ass to assemble, and the Geissele and MWI rods over the years. i find that they are much more useful for AR-10's and weird barrel profiles and custom upper receivers that aren't a typical profile more so than a generically useful tool for
every AR build or service work i do. the typical clamshell style one or the BEV block works for the home gamer doing their own AR work 9/10 of the time.
but to your specific problem: the spec for the barrel nut should be about 35-75 in-lbs.
not ft-lbs.
edit: correction here, my memory was bad and i confused ft-lb and in-lb here. the right spec is 35-80 ft-lb for the standard AR-15 barrel nut, generally you tighten to 35 ft-lb (about hand tight) and then rotate for the gas tube. this was pointed out in further posts.
if you torqued to 55 ft-lbs, this is over 650+ in-lbs and it's possible you may have stretched the threads or cross threaded the aluminum receiver with the steel barrel nut (and these are fine thread too, so less forgiving of crazy torque values). be very very specific in remembering
if you had an in-lb torque wrench, if you just mongo'd it on there with your arm and called it a day, or if you used a ft-lb torque wrench. a grown man can produce around 50 ft-lbs with one arm and an 8" spanner wrench, about half a again liquored up and two handing it.
if you did this, one option is to put some heat on the barrel nut (and aluminum flashing on anything you don't want to get hot) and heat the barrel nut and alternately tighten and loosen to work it a bit. this might take an hour or more. another option if you get no luck is to cut it off with a burr tool or dremel and cut off wheel and a steady hand. you don't need to cut all the way through, but enough to snap the nut with a crow's foot and breaker bar. the important bit here is your upper and barrel, not a $10 barrel nut.
