I don’t know about this one
I give you, the M-Lok compatible Auto-Ordnance Tactical Tommy Gun.
Yes, it is still .45ACP, still a semi-auto carbine (which is A-Os specialty these days post-Hughes) and still uses 50-round drums and 20-round sticks.
But everything else is, well, different.
More in my column at Guns.com if you are curious