A very hard thing even for the best of the best, I have never seen it, but have see a few seasoned shooters punch such tight group it is one small hole.
One such shooting friend puts 10, 6MM bullets in a group 3/4 inch at 200 yards with a handgun.
Something a bit better than my 1.25 inch group with a 22-250, same gun, same range.
(Yea,,I am a lousy shot)
How about vaporizing a Dinty Moor stew can with a .50 bmg at 1700 yards, that is a 1 mile shot but been done. Heard of a Canadian shooter beating that by a lot, a record I believe.
Do you know what such can looks like 1 mile away?,,It can't be seen with the naked eye.