I hope they work for you guys as well as it's been working for me. Hate to think of all the money you've wasted if not!
I'd been sort of thinking a scope with holdover marks would be ideal due to the trajectory of subsonic 10gn pellets with BC's around .020 or less. But now that I'm getting the hang of the rifle I'm not sure it matters due to the extremely limited ranges involved. Out to about 30m it shoots remarkably flat.
A 30m zero is also zeroed around 18m, and only drops about 65mm by 50m. A 50m zero though puts it about 40mm high around 30m and 50mm low by 60m, but I think 30m is about as far as I'm willing to use this against birds. Shots longer than that I'll use the .22LR.
At the muzzle, this has the same energy as a CCI Std Velocity still has at 900m, and that is bugger all. I Googled and learned that a .177" pellet can break the skin at 290fps, and fully penetrate at 330fps - which is around 150m.
"A series of tests were conducted to determine the velocities necessary for lead air gun pellets (calibers .177 and .22) and caliber .38 lead bullets to perforate skin.
Human lower extremities were used. Caliber .177 air gun pellets weighing 8.25 grains required a minimum velocity of 101 m/s (331 ft/s) to perforate skin. The energy per area of presentation ratio E/a was 1:86 m X kg/cm2. Caliber .22 air gun pellets weighing 16.5 grains needed a minimum velocity of 75 m/s (245 ft/s). The E/a was 1:3 m X kg/cm2. A round nose, caliber .38 lead bullet weighing 113 grains perforated skin at 58 m/s (191 ft/s). The E/a was 1.95 m X kg/cm2. These studies appear to indicate that lightweight projectiles need greater velocity to perforate skin than do larger caliber, heavier bullets."
https://www.researchgate.net/publication/16022563_Minimal_Velocities_Necessary_for_Perforation_of_Skin_by_Air_Gun_Pellets_and_BulletsRunning some ballistics shows that the absolute furthest the pellet can travel, pointed sixty-degrees into the sky, is about 350m maximum. The cheaper pellets with BC's around .014 are barely good for 200m.