We have a full time ballistics lab, where we test, and retest bullets to verify their BC. We do not accept any error over 1%. While a BC can change from a manufacturers lot to lot, we also update this information, its not a one and done kind of deal. On top of that, we use a ballistic algorithm that has been proven time and time again. It performed so well, that it was selected as the Scout Sniper Ballistic Computer by the Marine Corps.