The Hellfire is a Contract Killer Zombies weapon that resembles an M134 Minigun and holds 300 rounds. It is a huge weapon which is used to take down hordes of zombies. It costs 995 Gold to purchase. It does not start firing straight away, instead, it has to spool up. It is one of the highest damaging guns, and the barrel of the gun does not start spinning when equipped. Instead, it only starts spinning when the spool up sequence begins by holding down the fire button on the screen.
The Hellfire Limited is an upgraded version of the Hellfire, this time sporting a gold finish, has double the capacity, and is more powerful. It also costs 1,000 credits more. The description says it will be gone, but it does not look like it will be gone from the game.
Any gun with a "*" means it cannot be used by the player in-game. Any gun with a "**" means it got cut from the final game. Any gun with a "***" means it did not appear in the game, albeit only mentioned.