.380 might be popular in the real world, but we aren't talking about the real world here, we are talking about the dems world of criminality where all the gangsters have full auto MAC 10's and AK47's and they are gunning down school children to clear out their neighborhoods for selling crack. Never mind that there's only one case where an actual assault rifle was used in a crime, or that converting any number of the popular MAC 10's, AK, or Tec 9's to full auto is well beyond some street thugs capacity, they LOOK scary ok? Seriously, you know how hard it is to find a semi auto open bolt (if anyone cares why open bolt matters ...PM) MAC 10? People that got don't sell em, and if they do, they are expensive, and real full autos? LOL, $3000 is the cheapest I have seen one (also don't forget the $200 tax stamp, and actual rigorous background check), most start around $16,000, and go up to the high tens, and low hundreds of thousands since the '86 manufacture ban there is a set inventory available.
Back to the reality, .380, .22, 9mm, .40 all popular, and probably in that order, but not MAC 10's, AK, Tec 9's, why not? They are cheap, easy to get right? Ever been to a gun show? Not too many gangbangers there, and have you ever tried to conceal a MAC 10? They may be small, but they are NOT light, or thin, except the .... .380 version 🙂 Those little FNC's, Davis Arms, or any number of cheap, small, inexpensive .25, .32 .380 auto pistol is much easier to hide, buy, and get rid of than an UZI, but an UZI looks a lot scarier so it buy more political credit, never mind reality.