I received a longbow from a seller on that large auction site awhile ago...
Shipped in a large, heavy duty cardbord tube, bubble wrapped with the tube caps duct taped in place. It was obviously packed with care, but to loose in the tube and some US Postal idiot had apparently used it as SPEAR and thrown it into a truck or against a wall, HARD and the bow tip had poked through the bubble wrap, tube cap and multiple layers of duct tape. It was loose and slid back and forth in the big tube. No damage, but I was PO'd.
I think shipping bows is a matter of luck, despite how careful it is packed or who ships. I have bought numerous other bows in recent years, and they have all arrived in perfect condition.
PVC/bubble wrap and multiple prayers might be the best bet for shipping longbows.