Is a F03 version of the NV Debug Megapistol, works with the vanilla game.  My brothers main PC died the other day, and  he was having to use his laptop where he only had Fallout 3 installed not NV. He keep whining about not having the NV Debug Megapistol, so I made the vanilla Fallout 3 "Colonel Autumn's 10mm Pistol" as a Debug Megapistol the Damage doesn't reach as high as for NV but is likely the max damage for a F03 gun.

This is for Vanilla FO3 is just a esp.. 

Update
Ver. 1.1 Fixed the problem of the gun breaking after firing a single shot when not using God Mode.

Update 2
Ver. 1.2 adds an Invisible Scope from the Vanilla game, but requires archive invalidation to be set,
and the included Mesh file to be copied into your FO3 data folder under Meshes to uninstall is the same as the other file,
just remember to remove the Mesh folder too. 

You can use the Scope like a normal one just it isn't visible on the surface of the Gun as Vanilla F03 Doesn't have a model for the 10mm.  

This is a Cheat Item for those who wish to cheat, as it will likely kill anyone with only one shot, use the console code to get it  0006B531

To install copy the .esp to your FO3 data folder and click the box next to FO3 Debug Megapistol.esp in FOMM or under data from the FO3 Launcher.

To remove Just delete the .esp from you data Folder as there are not currently any other files.