I have had my WB since the summer and happy with it and probably will not evr change. I have noticed some wear on the black whiskers that support the arrow shaft. It looks like a 1/4 to half of the black whiskers are warn off from friction about 1/32" down. Just the front half of the whiskers are supporting the arrow. Is this normal wear? I do shoot ALOT so it may be time to change out disks??