Ahh Steve, now I read your statement correctly. The eyes only report what the mind allows. It's good when everyone is "right">!
Just out checking things
The cart nose at the valve inlet may be the variable that makes evaluation of this aspect of the valve just about impossible.
This aspect is evident between the first "piercing shot" and subsequent firings after fitting new carts. When the unpierced cart is pressed firmly to the valve inlet, that first shot "feels" weak. Has anyone bothered to measure mv under these conditions? After the piercing shot, I am sure clearances loosen up, but I have not noticed any rattling. Does pressurized CO2 offer some damping effect? I have no reference to it's viscosity.
Flow and go are nice. Reaching an efficiency target in grams/fpe would be pretty nice too. An understanding of all aspects would be a fun start. Think of the instrumentation one could put together
I will check the seal aperture on my unit when it is disassembled.
Wouldn't want to void the warranty you know
"A fool, persisting in folly, gains wisdom!"