I really have no idea about the accuracy.... I was just shooting indoors through the Chrony.... One ragged 9-shot hole of varying sizes at 20 feet, when shooting quickly a clip at a time.... I hope to swap out the valve stem tomorrow if I have time....
I should mention that each velocity plotted was the average of the 9 shot string.... Typical SD per string was about 2.0 +-.... Only a 5 bar (72 psi) drop for each 9 shot clip.... ie 8 psi per shot.... The .25 cal gets a few more shots from 230cc than the .22 cal gets from 180cc....
Bob