Gamma gun The gamma gun is a weapon in " Fallout 4 " . Characteristics . The gamma gun is a very crude weapon overall , and appears to have been built from scavenged junk found throughout the wasteland . The " dish " of the weapon is a small metal bowl with some metal wiring running towards the center and the central housing is a steel hexagonal structure with holes of varying size and shape . Assorted wiring , piping and other junk protrudes out of the rear of this structure , along with the three gamma round cells arranged in a triangular shape on top . The grip appears to be a handle - less spatula , welded onto a rectangular piece of metal pipe and stuck onto a piece of solid steel to unite it with the rest of the weapon . Even in their most basic form , gamma guns boast considerable radiation damage . Of course , this rare feature means most gamma guns have little effect on robots , ghouls , super mutants and the majority of wild creatures that plague the Commonwealth . However , most human enemies have limited radiation resistance . Even the most robust humans can often be defeated with several blasts from a properly modified gamma gun . The gamma gun launches a small blast of radiation damage that explodes on impact . Upon a direct hit , the target takes a significant dose of radiation poisoning ( 100 , or a 10 % loss in maximum health ) . The radiation - immunity - penetrating damage also means that the gamma gun will still do damage against radiation - immune enemies due to how radiation works in Fallout 4 , it will even do more damage against radiation - immune enemies than radiation resistant . Due to the potentially high amount of radiation poisoning the gamma gun can do ( upwards of 400 rads with a combination of Nuclear Physicist , mods and irradiated legendary prefix ) , this gun can be highly effective against tough enemies especially on high difficulties ( since radiation poisoning is unaffected by difficulty - based damage bonus / penalties ) , even with radiation resistance . In particular , extremely high level human foes may have close to or more than a thousand health ; as an extreme example a shot from a deep dish - modded and Nuclear Physicist - powered Gamma Gun ( 300 rads or 30 % health ) against a Gunner colonel ( 1070 health ) on Very Hard will be equivalent to 642 listed damage ( and equivalent to up to 428 on Survival mode ) . With the electric signal carrier antennae , the damage of the gamma gun changes dramatically ; it still does radiation poisoning on a direct hit , but now does a high amount of other damage that can be charged to do further energy damage . This essentially means that while the gun is still very effective against enemies with high health or relatively low radiation resistance , it also now does a significant amount of other damage to be useful in virtually all other cases . The downside to the weapon ' s power is the relative scarcity of its ammunition . While the Children of Atom - the primary faction that uses the gun - can be found in quite a few locations across the Commonwealth , they are formidable enemies and carry only small amounts of ammo . Purchasing gamma rounds from arms dealers may be necessary in order to use the weapon regularly . Weapon modifications . < section begin = " Gammamods " / > Footnote : The electric signal carrier antennae significantly changes how the gamma gun and the Lorenzo ' s Artifact version functions . The base damage changes to : In addition , if one holds down the fire button long enough for the gun to start making a " clicking " noise from the arcing electricity , it will do an additional + 45 on a direct hit . < section end = " Gammamods " / > Locations . Owned by Child of Atom cultists .