Even with the Automatic/Battle Rifle=Assault Rifle assumption, that still leaves you with a gun that's using a vastly overcomplicated cooling system for infantry work... or someone just decided to use a huge, solid barrel shroud because someone's a hurp-durp in the art department (and given that one of the upgrades for said shroud is something that would increase the cooling potential if it were used on, say, the actual barrel, this might even be the case). Either way, it's not a very good gun. It doesn't look sci-fi at all, even from a 50s perspective.
It honestly looks to be a variant of the pipe rifles that's a little bit more complicated. The barrel shroud literally looks like someone used a muffler, tin cans, or other scrap to make it depending on the mod, and the rest of the gun's craftsmanship doesn't even really match up since it actually looks like a properly built weapon.
The sights also make me angry. You put a reflex sight on and you've still got this hunk of metal in front of you. A hunk of metal that looks like a WW1 gunsight, I might add, which just makes it look even sillier.
Other than that, though, it's honestly a really nice weapon. I use it with single-fire mods because I like how quickly I can fire it when I'm dealing with lots of enemies but still take my time and snipe when I want to, and since I have Scrounger 4 the ammo is extremely abundant. I just wish it didn't look like someone found a receiver for a better gun and workshopped a bunch of crap onto it.