I've done all the Strikes in Vanguard Tiger with the Khostov… it's actually a pretty decent weapon, despite being the starter. This guy in the video was getting lots of bullets to the head, and was hitting a lot of shots in general. He also wasn't being stupid and standing out in the open, or getting within the range of Specials or Melee, most of the time.

i have to agree, the starting gun shouldnt even be damaging a high level player at all. or at least only doing 1 or 2 points of damage. Not doing the exzact same and in some cases more damage then there legendary/exotic (fully upgraded) level 20+ counter parts.