In the lumber mill buildings (the ones that have the saw/track in the center) - they have half open bay doors on one side and not on the other (other side is fully open).
When you try to shoot out (while standing) from inside the building, on the side that the door is fully open, it still stops the bullet for some reason. I assume it's because there is a "clipping" bar there that would indicate the door is partially closed when it isn't
I was up north, but one example is east of Stary Yar there is a lumber mill (top north borders of the map). I've reproduced it in multiple lumber mill buildings like this, but that is one I can easily reference you to since I was jut there.
Go inside the building, aim (while standing) out the bay of the door that is fully open. Shoot. It will stop the bullet. If you aim low it won't, as I assume it's because it thinks that's where the door stops at.