Keep in mind, that second video (from military.com) is a FIFTY CAL. Holy crap! It's the GAU-19/A - here is wikipedias page:
http://en.wikipedia.org/wiki/GAU-19
Never knew we had a .50 gatling gun, wow!
The 7.62 doesn't have much recoil, but it will go through an INSANE amount of ammo. Can't imaging anyone in the Twilight world having access to that amount of ammo, realistically.