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:
8754331--1186276--upload_2023-1-24_21-40-52.png
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)
8754331--1186291--upload_2023-1-24_21-48-40.png8754331--1186294--upload_2023-1-24_21-49-3.png8754331--1186297--upload_2023-1-24_21-49-22.png8754331--1186300--upload_2023-1-24_21-50-52.png

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

8754340–1186318–Culbar_Gun.rar (252 KB)