[adam731432]

That H&K UMP style full auto shotgun is bad arse but this will get the job done. Could possibly be owned as a civilian if you can find a multi caliber auto sear or full auto lower from a class 3 dealer and put it on a Saiga 12 semi .

 

[adam731432]

I believe he had one of those mags loaded up with 3 or 3 1/2 00 buck
There are videos of controlled fire on youtube. Probably bird shot.

20 round drum

Semi auto at high speed

3" Magnum shells

You can sustain these rates of fire easily with a semi auto saigia 12.