Niederlander
I must admit, Imma dry hole for your question. First Disclaimer: I don't own a Chronograph Machine. I have never own'ed a Chronograph Machine and admit I don't have a use for a Chronograph Machine.
Second Disclaimer: I don't shoot Trail Boss. In fact I have not shot a "smokeless" Fad, Heathen new fangled propellent in several Lustrum. When I did shoot that Fad Heathen stuff, I hated Trail Boss.
Last Disclaimer: I realize I have provided no help to the OP whatsoever. None. Nada. Zip. Zero. A dry hole. Of course, I knew that when I started this missive. One must understand, it's Tuesday Evening. I'm tired and bored and needed something to do. If you have read this missive to this point . . . it's too late. You're already here and can't recover. I have found however, so long as my projectiles reach all the way to the Wiley Steels, at Seven Yards, Chronograph information is superfluous. Just don't matter at all.