As far as close range guns go, it does the most damage for sure. I think if you land a full shot package headshot with it it does like 250 damage which is way more than needed to down someone. It's called the Mastiff, you can only get them out of supply drops that come down a few times each game. Though typically it's harder to find over the other gold guns which are a sniper and a light machine gun.

Definitely one of my favorites, though it can totally fuck you sometimes.