I shipped a longbow in a thick cardboard tube last week....it(the tube) arrived broken in half. Luckily the bow was undamaged.
I shipped a supply of 54 caliber lead roundballs, enclosed in heavy plastic boxes, 50 each, in heavy cardboard packaging and wrapped in multiple layers of duct tape. Inside one of the plastic boxes was a set of very hard-to-find brass scope mounts. I know they're very hard to find because they broke the cardboard outer box, lost ONE of the plastic boxes that was inside, and of course it was the one containing the very hard-to-find brass scope mounts....