I'm very interested in marksmanship but I really want to do long-range marksmanship. I'm thinking 700 to 1000 yards for competition later. I don't know where to start. Anyone have any good suggestions?
Record every shot, range (you can buy a laser rangefinder), your estimate (before you cheat with the rangefinder), windage, temp, humidity, exact bullet used (they *do* matter), time of day, direction of travel, and so on and so forth.
You can find tables for stuff like that for popular bullets, and how to apply them to your scope. (That's ballistics)
You can get app or calculator to do that, but again, doing it on paper makes sure you actually KNOW what to do instead of just going through the motions.