Bobblehead - Big Guns

Bobblehead - Big Guns is one of a total of twenty Vault Boy bobbleheads found throughout Fallout 3 and Fallout 4. In Fallout 3, it permanently increases the Lone Wanderer's Big Guns skill by 10, to a maximum of 100 and permanently increases 25% critical damage with Heavy Weapons in Fallout 4.

Location
In the basement of Fort Constantine's CO Quarters. To reach it, kill the protectron, which is usually found there, and then proceed down into the basement. Further down there will be an open safe on the left (literally open, not just one which has been unlocked). The bobblehead can be found standing in the safe along with a 10mm pistol and ammunition along with the Fort Constantine launch codes and some caps.

Gallery
Wackelpuppe - Große Waffen Пупс «Тяжёлое оружие»