You got me interested so I took my 300s out . Put a target I printed off the internet , labeled as 10 M air gun, nice big bullseye, which turned out to be too large. I'm 75 and getting over cataract surgery, I had my right eye(dominate) done a little over a month ago and the second two weeks ago. I got some inflammation in the cornea on the right eye so every thing looked blurry until just a couple of days ago and still not quite as good as the left, plus about 12-14 years ago I had what they called detached viterous humor first in the right eye then in the left eye about a year later, which left me with thousands of floaters, the largest and worst in my right eye. Well today, I never did hit the what looked like a 1/4" ten ring, kissed the 9 a few times and most were in the 8 ring, lets don't count the flyers , I did keep everything in the black on about a 3 1/2" bull. I really need a smaller bullseye for my double aperture as I was really guessing, could not get the proper white ring around the black bull. I even tried backing off to about 15 yards and it is still too large..
I'm thinking that I may take one target and cut the bullseye out and trim around , then tape it onto a sheet of paper and see how it looks with my sights at 10 meters, and if not good trim another ring off and keep trying until I can get a proper size for the sight.
I still get more enjoyment out of shooting good iron sights than optics. Starting college back in 1963 I was pretty good shooting the Marlin 39a Dad and I had, then I got on the ROTC rifle team and learned position shooting and how to use those double aperture sights and have always liked them for target work, even some plinking on tin cans, ect.