Distance from muzzle to chrony
I agree with the statement that distance to chrony is important. I like 12-15 feet. That way there is less liklihood of little chunks of material throwing off your readings.
That said, I look through my notebook every now and then to review the various loads I have chronied, and it is funny how many times there is a nasty swear word printed next to the velocities column because of bogus readings. Sometimes for no reason whatever the screen will flash error. Other times it will show exactly the same velocity for 3 rounds in a row. That seems highly unlikely to me.
Chronies are just another tool, and darn sure not the end all-do all of hand loading. Good accuracy and experience with a load like the OP has used is the most important thing.