I must be mising something. The Uzi is available in multiple chamberings, including the 9mm Parabellum and .45 ACP. The Mini Uzi is 9mm.
How is 9mm or .45 ACP fired from a faux SMG less loud than the same round fired from a 1911 or a Glock?
My guess is barrel length providing a modicum of difference. Avg self defense pistol being 3-5 inches max where as avg UZI like SMG/Semi pistol having a 7-10 inch barrel.
All that said I literally cannot imagine an instance where I would choose something like a semi auto MAC/UZI etc. pistol over any decent handgun. As for full auto pistols ala Glock 18/93R etc. I can’t imagine using them on full auto for anything except giggle factor at the range and having done my fair share of full auto across the board that actually gets old fairly fast and becomes money into noise.
Now if we are talking PURELY for a fun oddity sure, why not. If we are talking about a stocked 16inch PCC absolutely both fun and useable.
We won’t even speak of the TEC9.