http://www.kel-tec-cnc.com/sub2000.htmWe have two of them and they have been good little carbines. Ugly, but they work.
My wife has an older (and better, IMO, but long-since discontinued) SUB-9 that uses S&W mags (to match her CCW pistols) and loves the thing.
I have a current SUB-2000 model that uses Glock mags (to match my CCW pistols) and was very happy with it until the Oly GL-1 ARs came out (which also use unmodified Glock mags). I hardly shoot the thing since getting the GL-1s but the SUB will still stow and travel in places I could never carry an AR, so I still keep it around.
I have no personal experience with the on set up for Beretta mags, but I have no reason to expect anything different from them. (I came across a used one at a gun show last year and, if I hadn't already had a Storm, I probably would have bought it on general principle.
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