The gun is essentially an M1911 that shoots rifle grenades. It fires the same way as the player's pistol does when downed and the Suicide King Death Card is also enabled. The player can also acquire it through the developer console on PC.
In Call of Duty: Black Ops, the Dirty Harry functions similarly to the Call of Duty: World at War version. It can be found by using the "give all" command. Upon entering the command, the user will receive all guns, including Mustang and Sally. The first one operates as normal, but upon equipping the second one, the left-hand pistol will disappear and only the right-hand pistol will be visible, although both triggers will fire a grenade. The grenades are invisible, do much less damage than the real Mustang and Sally (requiring multiple grenades to kill a zombie even in the first rounds) and seem to travel a lot slower as well. The weapon has no reload animation or sound either. However, on iOS the Dirty Harry is the pack-a-punched version of the M1911 since dual wielding was Impossible on iOS.
Due to the fact that the Dirty Harry was never meant to be used while standing up, several graphical quirks exist with this weapon. For instance, when sprinting with this weapon, the player holds the weapon down as if they were using an M1 Garand with rifle grenade, the reloading animation is the same for empty and non-empty magazines and from third person, the player appears to throw a grenade whenever the weapon is fired.
Other quirks in third person include when in ADS and moving, the player seems to walk in a rather bizarre way, almost gorilla-like movements, arms suspended in the air and legs spread open and it appears as if the player is walking while crouched.
While in third person and crouching (not ADS) the Gun will appear at the side of the player, above their left shoulder.