1 same animation is applied to both arms and weapon. The mesh for the arms was separated so that it can be modified easily without having to modify the arms mesh on every weapon. So it is 1 same skeleton for the arms and all the weapons. You can check the tutorial series, there is an episode with changing the mesh and animation for the shotgun and also an episode of making and adding a new weapon! https://www.youtube.com/playlist?lis…BZjibaE5DCP4pp