In my earliesd days in Vermont at the deer camp with my Dad, Uncle Jack and Hubert Simons (the owner of the camp) they were tossing soda cans up over the meadow in front of the camp and shooting a .22 rifle at them, hitting most of them. I think I was twelve or so and said I'd like to try. They passed me the rifle and a .22 Long. A can was tossed out over the meadow, I took careful aim, touched the trigger and the can went spinning wildly off its original course. Well the men seemed pretty shocked and asked me to try it again, knowing full well that I could never repeat the shot. I was passed another bullet and I tucked it in the chamber, closed the bolt and yelled "Throw it!" The can sailed out over the field and once again I took careful aim, touched the trigger just as I had done the first time and the can (amazingly) went twirling straight up then straight down. The men were dumbfounded.... How could this boy repeat that difficult shot a second time...? A while later my Dad levelled with me. They were passing me .22 Longs all the while they were using .22 birdshot
I still have an article that tells about the BB to BB training for the special forces in Viet Nam and the article goes on to say that another form of practice was th shoot an aspirin tossed perpendicular to the BB-gun shooter much like a clay target at station 4 on a skeet range and the shooters averaged 80% or better. The premise was that the center of any target, whether stationary of moving, is exactly the same size... infinitesimally small.