The United States Bowling Congress has revoked approval of Purple Hammer bowling balls manufactured in 2016 and 2017. These model years are removed from the list of balls approved for USBC competition effective March 21, 2022. These model years of the Purple Hammer may no longer be used in any USBC-certified competition, including all USBC leagues and tournaments.
Purple Hammer bowling balls manufactured during 2016 or 2017 are identified by serial numbers that start with either a “6” or “7.”
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