Velocity Truing
Adjusting the muzzle velocity or BC in a ballistic solver until its predictions match your real impacts at distance.
Velocity truing is the process of nudging the velocity figure (and sometimes the ballistic coefficient) inside a ballistic solver until its predicted drops line up with the corrections you actually need on target. Even a good chronograph reading can be a few feet per second off, and that small error compounds the farther the bullet flies, so the solver may call the wrong elevation past the transonic region. Shooting a known distance, recording the true correction, and letting the solver back-solve for velocity closes that gap.
The honest way to true is to confirm at multiple distances rather than forcing a single far point to agree. If the supersonic drops match but the far ones do not, the drag model is the culprit and BC truing is the better lever. Once trued, the solution should track your dope across the whole usable range, not just at the one yardage you tested.