Wrong raycast direction on an object which is rotated to match slope terrain

This object is rotated to match the terrain slope by a basic script and moved to the target by NavMeshAgent. When shooting, a raycast should go in direction of the rifle. But, as you see from the photos, the raycast goes as if the object is not rotated at all. The raycast origin is an empty game object which is a child of the rifle's pivot and it is located at the muzzle of the rifle. I tried several things such as changing parent object of raycast origin, but didn't work.

If you have any suggestions, please help me. Thank you.