I've yet to see an AR weigh on my scales at 5.5 lbs ...
There can't be many. G&A says the MI they tested was less than 5.25 lbs. Most of the ARs I've picked up have felt well over that, but in fairness, they mostly have a lot of gear bolted to them so it's hard to judge.
Barrel weights from the makers are all over the map, but you occasionally see one advertised at 1.5 lbs.
I'm going to talk to the gunsmith who built my .223 Remington bolt action rifle about this. He does up some heavy barrel ARs for long-distance match shooting, and he'll surely have an opinion as to this one way or another. Probably a negative one, given his predilections.
