[Rainbow Demon]

I have a Romac with the usual problem of canted front sight base.
The problem is that this particular rifle has the cut off flash hider (forming a barrel nut) welded to the sight base with a thick bead in the clearing rod track. The weld doesn't obstruct the end of the rod, but would make any effort to straighten the front sight base difficult.

My question is whether this weld goes on through to the barrel?

This particular rifle is uncomonly accurate for the type, so I suspect the weld didn't touch the barrel, or at least not enough to heat the barrel steel much.

I'd like to remove this barrel nut and preserve as much of the threading as possible.

Another question, would there be any legality issues if I installed a flash hider or muzzle brake?
I'd just as soon find a better looking barrel nut, a flash hider isn't that important for my purposes.

PS
While the magazine that came with the rifle was a very loose fit a spare mag that came with it fits just fine with only a tiny amount of wiggle. I figure the magazines are the problem there rather than the mag well.
Looks like they may have scrubbed the side plates of the mags to remove markings, leaving them a loose fit.