Nice M2 HB Browing!
Just a note as I'm not sure what version was used on the Vengence, but you show the infantry, ship or vehicle mounted M2 HB.
The aviation version of the M2 had the perforated barrel jacket and it's attendent barrel bushing extened out to the muzzle of its slightly shorter barrel. Other than that, they were pretty much the same with the exeption of the solenoid fired M2s in the fighter planes. those had a different base plate with the electrical trigger (solenoid), but were otherwise the aviation version of the M2.
http://www.youtube.com/watch?v=29n_niWpHI4&NR=1