Where can you find fat men in fallout 3?

Answer 1

If you mean fat men as in the ones that shoot mini nukes, you can find one in the Chevy chase. I think another one can be found in the same area as the t-51b power armor in Fort Constantine. And a unique fat man called the Experimental MIRV can be found at the National Guard Depot but you need all 5 Keller diaries. The gun shoots 8 mini nuke at a time (good for leveling a town). And i think there might be one in the talon company merc place.