"Cowboys can't shoot slow or they'll end up below. When they need some help, they reach for the root beer shelf (Yee-haw!). Cowboys can't shoot slow, or they'll end up below, (below?) when they need some help, they reach for the root beer shelf. YA THIRSTY PARTNER!?"
Double Tap Root Beer is a canon perk that appears in all Canon Zombie maps except for Nacht der Untoten and Ascension. The perk increases the rate of fire on all guns by 33%, essentially being a copy of the Multiplayer perk Double Tap. For some, it is considered an 'ammo waster' due to all guns receiving a high rate of fire. This fact is often disputed as a gun only fires as long as a player wants it to.
Double Tap II
In Black Ops II, Double Tap returns as Double Tap II Root Beer. Instead of simply increasing a weapon's rate of fire, it fires two rounds simultaneously for each round fired, effectively doubling damage. However, this effect doesn't apply to the Ray Gun, the RPG, the Ballistic Knife, Mustang & Sally, or anything with similar effects.
Dempsey remarks that it tastes chewy. This is possibly because the roots aren't ground.
It is the only original perk not to feature in all maps.
This is Richtofen's favorite perk. However, it seems he dislikes the jingle.