"Thanks sscoyote, I will try the measurement at 100yrd AM. I will be able to do this in my yard. I will post what I find. Bill Maylor"
I've found a good place to practice rangefinding with reticles is often right out the window of my old house (assuming discretion, of course). When i was studying this part of the LR shooting game, i was looking out the front window of my old house 1 day when i noticed all the signs that were along the street that ran more than 1000 yds. away from my house. All i had to do was go out and measure them and range back to my dining room window. What i'd done really was established a sort of "optics lab" with different stds. that i could use to play with my optics. It was really a great project. Once i knew the subtension of my reticles it was easy to reticle-range these signs and see how close i could come to the true (lasered) range. Then once i figured out that reticle subtension changes porportionally with magnification change it really got fun. Now i could take a 3-9X plex-reticled scope that i knew the subtensions of, and calculate a power that would be needed to bracket a certain sign at a certain distance--drove my wife crazy for awhile, i tell ya'.
Interestingly i often wanted to help my buddies when they came over the house to help them establish a long-range shooting system with their plex-reticled scopes too (usually for coyote hunting
during the winter). The problem was if they were using an optic that we didn't know the subtension of (many scope companies have the subtensions advertised in their catalogs), then i didn't know how to measure it really at the time. 1 day i was riding my bike down the road when i stopped at an intersection. I looked over at the stop sign and there was my answer. Many road signs use posts that have .25" holes drilled in them at 1" intervals, and there was 1 out in front of my house at something like 95 yds, i think it was. I used that "std." many times after that, and could get measurements off those holes when the light was right.