I've been playing around with ChairGun looking at various combinations for HFT with my Kral Mega. Using it's "Optimum Zero Range" app gives very different zeros using different kill zone sizes. See images below.
What size KZ do you guys use for FT? Do you even use CG to figure out your optimum zero?
EDIT: Sorry, I messed up with the CG screen shots with the KZ not being changed. I then tried to modify the images but ended up adding two more. The bottom two are the correct images.
I don't own ant PCPs (never have) however I didn't find that ChairGun was matched my real world trajectory chart but when using CG to get a "rough guess" I always set up ChairGun with a 1/4" killzone using the ballistic coefficient derived by getting the velocity readings at two positions 30 yards apart using the CG app, then "massaging" the BC till the trajectory matched the shot target..
Since it was a hassle to get precise trajectories using CG and since I needed to shoot a "verification target" anyway I stopped using "puter output" and only shot "real world" trjactory targets like this one I made using some CAD software. Target shot with my .177 R9, 7.9 grain die lot marked and dated Crosman Premiers, zero'd at 30 yards with scope center mounted 1 3/4" above the bore and sitting on a bucket resting the gun on cross sticks HFT style..........
Bottom line, I only use actual shot targets to determine pellet trajectory!