I haven't tried that loading, but I've chrono'd other calibers - .380, 9mm, .357 shot from the same gun or barrel length he used (he usually names the gun used in his velocity testing) and they were within 10-20 fps of what he published. If barrel length is not the same, I've often seen 40-50 fps slower cited for every barrel inch shorter.
He's proud of his product - call him up with your info and ask him. I'll think he'll be glad you are interested.