I shot this weekend with my new "big gun," and was explaining to another shooter behind the line the actual significance of what we were doing - looking through the spotting scope, we tend to lose perspective on just far apart are our line of sight and our bullet trajectory when we are shooting long, long distances.
I had an opportunity to shoot 2913yrds this weekend, and for my first round impact on the target, I sent 35.5 mils of correction (I dialed 30.5mils on my scope, since my capacity was only 32.5), then held 5 mils in the reticle. Thinking of 5 mils in the optic, that really didn't feel like too much - not so different than when I HOLD OVER from my 100yrd zero when shooting at ~750yrds, since both would be a 5mil hold in the reticle... but recalling the 30.5mils extra dialed, PLUS the 5 mils held, totaling 35.5, I had to acknowledge that I was actually aiming my bore more than100yrds (310ft 3in, to be exact), higher than the 48" target (1.6moa at 2913yrds).
Not very often in my life have I had opportunity to need to hold 100yrds ABOVE target to guide bullets where I wanted them to go. It's a really intense experience.