Buckslayer,
I will try to answer your question the best I can, I was in the Marine Corps during that time and our snipers used 10X scopes. Carlos had just won the Wimberton Trophy at Camp Perry I believe the year before or might have been two years. That's shooting at the 1000 yard line.
First of all back in those days all Marines qualifed with the M-1 Garand and then later the M-14 and you fired at the 200, 300, and 500 yard line with open sights. Each Marine kept his own dope book that Marine Corps issued. So had any given yard line you knew what your come ups were and your windage, now saying that you also had to put in for windage on that day you where shooting depending on which direction and how hard the wind was blowing, we were taught to read the wind. After you qualification day you had a little card that you filled out with the dope and you put in your battle sights on the card which was for 300 yards. This card went into the stock so if you were killed another Marine could pick up your rifle run the elevation and windage knobs down to zero and reset for 300 yard.
Now with the snipers this was taken even further with the Winchester 30-06's and they all had their dope (come ups/windage, etc.) in their book on that rifle and what their come up's where at a given range plus they could also set the scope at a given come up to shoot dead on out to say 300 yards. It's really not that hard, you just practice alot during it and it becomes second nature to you. If I zero my rifle in for 3 inches high at 100 yards, I can hold dead on in the chest area of a man and get a clean kill, alot like hunting where you have an 18" kill zone. The biggest problem is the wind since the chest is not has wide has a deer/elk, you have less room for error not the elevation.
Both of my son's our snipers in the Army until one became an officer and starting flying chopters, but they practice everyday on shooting at different yards. I hope this answers your question somewhat.
dbuck
