Colonel Autumn's Laser Pistol (Fallout 3)

Summary
A weapon found on the Enclave Leader, Colonel Autumn. Bears very similar resemblance to the standard laser pistol.

Weapon Details
Colonel Autumn's Laser pistol is a modified, fully automatic version of the standard pistol.

The laser pistol does 75 damage, a drastic increase over the normal Laser Pistol, while using the same Energy Cell ammo as a standard pistol. This version also has a weight of 2, compared to the standard version's 3.

It is only found on Colonel Autumn in the Jefferson Memorial Rotunda during the final quest. As such, unless you cheat to get it, the only way to get it on the console versions, is to glitch up a rock and get through a tiny opening in the barrier and kill him prematurely and leave, there is no other way to get it.