Per the picture, the AR is a, perhaps, 9mm, with a staggered mag.
ARs can be built with a variety of uppers, in a vast selection of chamberings.
16 posted on 03/28/2024 3:26:14 AM PDT by jonascord
(First rule of the Dunning-Kruger Club is that you do not know you are in the Dunning-Kruger club.)