WOW!!! All the information response is like attending an Airgun seminar!! I will print this. Thank you very much.
Knowing your equipment and purpose would help.
I was looking for info like this when I bought my first PCP. The folks here at AGN told me that I needed a chronograph to troubleshoot and see issues.so I bought an FX pocket chrony.
My use was plinking, and I was very dissatisfied with my new rifle. It was unregulatd, and the point of impact would fall for each shot. The chrony just showed the same thing in fps.
Studying it, I found that the model I had came with an adjustable hammer tension that could be set lighter so that hammer didn't release as much air. The higher the gun pressure, the harder it is for the hammer to open the valve. This is the principle used to regulate an unregulated gun, as well as one of the building blocks of adjusting a regulated gun.
With a lighter hammer weight, less.air is released, so you start with a lower fps.
As the pressure drops, the hammer over comes it releasing more air, increasing fps to a max point, and then the pressure and fps drop.
My goal with this info was to to get the highest shot count in the optimum accuracy range.
The fps change was pretty great here so, what if I wanted to hunt ?
There are about 8 shots at the top of the string at the highest power level with a good fpe. More fpe could probably be had with more adjusting, but the shot count would likley drop, and it is almost a full mag at the current setting.
So I would have to note the pressure of the gun at the point where those shots start and set that pressure, then I would have one mag of the most consistent and powerful shots that the gun is capable of.
Its all in the soup ingredients.
buck-rail.com 
