Question Blender to Unity .FBX -> Model not as it should be

Hello, i am a new newb trying to make 3D games on Unity, and like the most newbs, stuck at a basic things, i am facing the problem that my Blender Model is somehow in wrong offset, some parts are rotated, others are changed location:

This is a basic gun i made to learn Unity without depending on junk from the internet, not much efford now, just made an Action for Reload (The Model has 2 Actions, one for the recoil from slamming the Mag in, and one for changing the mag/Getting the mag out of the gun and back in)

Now i faced already a problem where the Model was really cringe in unity, but i could fix it by "Applying Roation/Scale" on every Mesh (I wanted to do it on the Armature, but it would mess the whole gun up)


How you can see, the whole Model is still crazy in the wrong offset, i don't have any backfacing problems but i don't know at all why it's messed up like this, so i need help with this.

Since i don't know at all why it is messed up, i can't give information on it. i only can show what is happening with the Model, and what i found so far on Google(Apply Rotation/Scale, Backfacing, fbx export settings).

 

Max Upload limit are 5 Files, here is the .blend file for the gun