H4mmer

 is a gun that fires a barrage of bullets. The last shot in the magazine is a hammer, which deals extra damage and can stun enemies.

Bugs

 * There is an issue with the synergy where if the ammo count exceeds what the base gun would have without the 50% maximum ammo, the current ammo count would revert to that amount. Additionally, partial ammo kits cannot have the ammo go above the base gun's amount, unless it is applied to H4mmer itself.

Trivia

 * This gun could be a reference to the Call of Duty®: Black Ops II gun named "HAMR".
 * The description is most likely a reference to 'fanning the hammer', which is done to make a revolver fire faster. In this case, it is a fully automatic revolver.