You two are missing each other on this point. The pressure data John Barsness posted features revolvers with different barrel lengths.


Max Prasac

Semper Fidelis

The Gun Digest Book of Hunting Revolvers:
https://youtu.be/zKJbjjPaNUE

Bovine Bullet Test
https://www.youtube.com/watch?v=mmtZky8T7-k&t=35s

Gun Digest TV's Modern Shooter:
https://www.youtube.com/watch?v=nGo-KMpXPpA&t=7s