In gaming, a "mod" (short for modification) refers to any change made to a game’s code or assets. "Gun mods" are among the most popular types of user-created content.
You cannot install a new trigger, swap a barrel, or add a compensator and assume the gun is safe. Gun Mods
If you install a new rifle barrel (or a 22LR conversion kit), you must check "headspace." Incorrect headspace causes case ruptures, sending hot gas and brass shrapnel into your face. In gaming, a "mod" (short for modification) refers