When you press F11 twice you'll always see the bounding box. Seeing a bounding box does not mean that the entity does not have the POLYGON flag set. So you cannot jump to conclusion from that. Are you experiencing trouble with the collision detection?

Your action BBRail01short is most likely not doing what you expect it to do. Letting the engine automatically determine the hull of an entity and then overwriting these values by hand seems not useful to me.

I'd also recommend setting the entities center always inside it's bounds, mostly centered.