I had forgotten this bit of long range shooting - when we were young, Taylor and I used to shoot at a light coloured chunk of granite in the middle of a large V shaped spread of very dark, almost black earth. The rock was between about 15" and 20" in diameter and was about 325yards distance. It was difficult to tell it's exact size, but over the course of a summer, we managed to cover it with lead.
It was elevated slightly form line of sight, about 20 degrees, and paced, about 315 yards/or meters (long steps) to the base of the granite face to the firing line. My paces when doing this come out very close to my range finder. I'm usually in the middle between yards and meters. The rock was up around 60 to 75 feet above the ground on the granite face in a V of dirt filling a depression, back a bit form the front edge = perhaps 25 to 30feet, hense the "about" 325yards range we called the shot.
We were able to hit it often with my .50 cal. Plains Rifle, Taylors .62 Hawken and my wifes' .36 Seneca with 128gr. slugs. I could not hit it with the .36 RBalls though - no idea where they were going, but suffice to say, I could have been in that dirt but couldn't see the strikes. We were able to walk our shots up onto the rock - easier than mere guessing. I'd forgotten about this 'feat' we used to do 'at will', when I posted the statement above.
Of course, neither of us shoot that well, today however I did manage about a 4' square steel plate, 2 out of 3 shots at around 300yards, offhand, with my .69, at Hefley Creek Rondy. Wind was a definite problem at that range. With the .58 Double Rifle, I came close, but no cigar. I say 'about' as when we measured it, we are 'about' 75 yards behind that firing line and off to one side a ways. It ranged 408yards on the 1,200yard Leica range finder.