I need the medium size for the Beman ICS Hunter and Hunter Jr.'s. Is this the same size needed for the Carbon Express arrows as well? The reason I ask, is that I am looking for a used WB for my young son's new bow, and a gentleman has contacted my regarding his WB. He used it with Carbon Express arrows, and thought it was a small diameter hole, but I'm hoping it is a medium. Do the Carbon Express arrows have a small diameter than the Beman ICS Hunters? Thanks.