Unity distorts FBX Model and Animations?

I have an FBX containing a set of arms and a handgun, including basic animations (walk, reload, shoot etc.) but whenever I import them, the arms are all messed up and distorted.

I've tried resetting the location rotation and scale of the meshes to 0 and then exporting (using blender), but it just does the same thing. The arms and gun are all seperate meshes. Would I have to export each seperate mesh as an individual fbx, just to get this to work?

I've been looking for hours, this is my last resort, please help!

EDIT: I found the source of the problem, but still no solution. I attached a script to the fbx to play the reload anim when you press "r". The gun is in the correct position and animates fine, but its the arms that are messing everything up. When the anim plays, the arms do the same movements as the clip of the gun.

SOLUTION:

Finally found a solution. The mesh had two separate armatures, unity didnt like that.