I finally got the time the new Chrony and the Gamo together. The Gamo got from 935 fps to 991 fps with different regular pellets of different types and weights. With the Viper inserted blunt end first was between 338 fps and 365 fps (10 shots)
Surprisingly The fastest pellet was the cheap "Made in China" pellets I picked up at a gunshow for $7.00 for 5000.

I am getting used to the Chrony and checked some 45/70 loads in the Gibbs. I was shooting some 500 Gr. at 1585 and the brass buttplate didn't bother me at all. (I may be getting numb).