Precise velocities aren't the same as accurate velocities
^^^ I don't what your after on that one.
The velocities that I get with the Labradar jive with known BC's when calculating a drop chart, due to the ease of recording every shot , a velocity average can be determined over a large sample size.
With this confidence in velocity other changes are much easier to see.
So if I have an ES of 20fps, over 100 shots I will average them , the velocity could be 2952fps. This is what I use to calculate BC's for external ballistics and Quickload for internal ballistics.
The lower the ES the better it will be for calculating either.
While not perfect it is much better than what has gone before.
If the math doesn't work then suspect inaccurate/precise velocity readings.
Its the foundation.
