All the cool kids have them.
WTF is an assault rifle-style pistol?
It’s an AR-forty-16 chambered in thirty-ought-12 gauge. Has a belt-fed high capacity magazine, “shoulder thing that goes up,” and a bayonet lug. Oh yeah, and it’s a ghost gun with absolutely no metal parts and is invisible to x-ray machines.
It is a description of a firearm by someone who has no clue of what they are talking about. Probably a Glock. Glocks make all kinds of assault weapons. Everything from assault style water guns to 50 cal blunderbusses.
All the cool kids have them.
Stocked rifles with barrels under a certain length are illegal. So people who think they need such a thing contrive powerful, high-capacity “pistols” by combining an AR15 lower, a buffer tube without a buttstock, and a short upper with a 10”-ish barrel. These are often used with some sort of unattached “brace”, to afford stability. There are similar “pistols”, using short-barrelled AKs without buttstocks.
These things seem useless for any purpose other than spraying a crowd, but I’m sure some folks justify them.