Good post.
My problem is I have no place to sight in at 100 much less 200-300.
I sighted in my sons Rossi 243 Thursday with a new scope. I started at about 25 yds. It was about 10" high. Got it to about 1" high. At about 50 yds it was still a little high. I feel like it will be dead on at 100. (Took me 12 rounds.) BTW where we hunt most shots are within bow range on small East TX. Whitetails and pigs. Using this method of sighting in, I have killed a deer at around 180yds once using a 742 Woodmaster in 243.
I know this isnt by the book method but it works for me. I wish I had a place to shoot long range. Also before I get slammed my son is 8 and the 243 is about as much recoil he can stand and shoot accuratly. There are better rounds for short range but not for him at this time.