Re: long range shooting
Bruce, I have a Leopold that the last 5moa is useless too...
I like the top of the plywood as a target, it makes a very clear line to hold from and the drop down from there is much more pronounced than the 600 yd zero gives because the bullets are impacting on the target on their way upto the max ordinate and on their way down too, easy to mix up groups and their closer together as well.
The 600 yrd group works out close to the bottom on a sheet of plywood depending on the cartridge used and groups are decending and easily kept track of too. I start by covering a sheet with two rows of frezer paper taped together, front and back, and stapled to the sheet. My 100yd zero is already established so I go to 200, 300, 400, 500 and 600, as fast as I can move and get setup again firing 3-5rds at each distance. Seeing the bullet holes in the freezer paper makes it much easier to plot velocities for each shot on a tablets target with relation to each round fired if you do this. Measure the groups center to center and you have it.
Do this at various temps, BP (and angles if an option) and you can develope super accrate drop charts and verify the accuracy of your programs modification of various temp, BP and angles too. If you use a crony doing it you'll have accurate velocities to input at the different temps as well, which will help you enormously.