The final fix from the trajectory math & logic audit — velocity truing.
/v1/true-velocity computed drop from the bore line of departure rather than the line of sight, so the effective velocity it returned did not reproduce the measured drop in the app's own dope. Truing a 5.1 mil measurement returned 2721 fps, yet the dope at 2721 fps is only ~3.9 mil — so a shooter truing to that value would still miss. It now uses the line-of-sight drop, and the round trip is exact: the dope at 2700 fps is 3.871 mil, and truing 3.871 mil recovers 2701 fps.warning and marks the result low-confidence, telling the shooter their ballistic coefficient is likely off rather than their muzzle velocity.