Re: Bullet stability
I have had loads that by judging at 100yards I would think were worthless that I knew were on the edge of the limit. Bullets were slightly keyholed at 100 yards while perfectly straight on at 300 with good accuracy. In my experience, bullets tend to stabilize more down range, even though velocity is decaying. Even if on the edge. I have only had one load that never stabilized and that was the old Barnes XFB 200 grain shot out of a 12 twist 308. They hit the target sideways at 25 yards.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.