A little measureing today while I shot all three scopes (and considering there was a swirling head wind, was a pretty good day).
The wide spacing of the 6X BugBuster gives something close to 7.5MOA between dots. For airguns, can consider that something close to 3.75-3.8" at 50yards.
The center spacing of that 10X is runing right at 3.3MOA..call it 1.65" at 50yards. IF I could think in metric, would probably work out to some more even number (and it's an eyeball/home amde grid estimation anyway, so kind of ignore that last digit.)
The little 6x at the bottom is running 3MOA, or about 1 1/2" at 50yards per hash-mark.
Used the same rifle for all three (an RWS 75) to keep it more apples-to-apples (and whent back to match apature at the end of the day...like that rifle with iron).