M2HB is TALL.

As long as we're naming every weapon here, the gun behind Homura's left leg is the Kriss Vector SMG, specifically the Super V:
http://www.kriss-tdi.com/products/kriss-smg-45-acp.html

i think the kriss vector is also the tdi_vector. but i'll use the latter one because someone already used it. in case they're totally different, feel free to correct me. i apologize and thank you.

Yep, it's the same gun, apparently TDI became KRISS-TDI. And I could have sworn I did a wiki search on Vector and came up with nothing, had I known the tdi_vector tag already existed I would have used it.