But seemingly, the one factor no one wants to address, is the shooter!
Exactly. It is the shooter that is the most crucial variable as I've always said.
Head size doesn't matter if the pellets fit snuggly--not loose--in the barrel. I wonder if shooters even think that regardless of pellet head size, whether some are a couple tenths larger or smaller than the rest, the pellets are still going to lose some of their material anyway when they are shot out of the barrel because before exit they will have gone through serious friction being dragged against the bore's internal surface, thus scrubbing off some lead (decreasing its weight) and then getting resized in the process.
My Cricket has been powered down to shoot at only 8 FPE (or 502 FPS with 16-grain pellets) and, with no intention of being arrogant, I can hit the tip of a palm leaf at 40 yards repeatedly--yes, regardless of pellet head size! (Again, as long as they are not loose-fitting.) But this is possible only because I had to spend an enormous amount of time practicing and learning in the process. And having said this, I state the above with confidence because a long time ago I too used to think that this phenomenon was a reality. But after much training, I've seen the light.
I know there will be others who will disagree with me. To them I say I trust instead the experience I've gained from the years-long training (and continue to go through) to reveal to me the truth. There's the adage that expresses something like "time does things to a person and can change him or her." You know, experience does so too.
With genuine respect to all shooters, novice and professional,
Spinj