I let my ballistics program tell me how fast things are moving down range. If you use a scope that tracks precisely, several apps will true velocity for you using known BCs and good impact data.
John
Many variables go into the ballistics programs. I'm interested whether anybody checks the program's math by measuring actual downrange velocity to confirm correlation with prediction. Otherwise stated, unless every single ballistics program provides the exact same answer @500 yards, that's where model validation comes in.
