The gun, in a user-made build. The Akimbo version is similar, except it has a dark blue coloring.

The Guns Akimbo is a default weapon that uses two Guns in both hands, giving double the rate of fire and damage per second. The right hand Gun fires on click, and the left hand Gun fires on release. Surprisingly, tests with ammo mod have shown that the Guns Akimbo has a max ammo of 99 bullets. Logically, the Guns Akimbo should have twice the ammo(60 x 2 = 120) of the Gun. While this gives you 39 more shots over the Gun, you lose 21(about 16%) from the expected 120.