While the parabolic natural log calculations have merit, a much larger effect on vertical dispersion is the vertical wonkiness factor or VWF. When it approaches infinity the rotational portion of projectile repeatability increases exponentially, and may have influenced the results observed by the shooter at 300 yards. To complicate matters, the VWF and HWF (horizontal wonkiness factor) interactionally inversely influence each other, forming the total tangential wonkiness factor, TTWF. When TTWF approaches 1.0000000 use extreme caution as point of impact could be almost anywhere, and the group size approaches infinity.
Another force may be in play here as well; the trigger spring twanger tension, TSTT. It can be influenced by any number of things such as the change in density, viscosity, shear force etc. of the lubrication in the mechanism, relative expansion/contraction in the steel, aluminum, plastic parts, and more. All of these are sensitive to temperature, pressure, dew point, phase of the moon, velocity of the trigger pull, and general wiggling around on the bench. A simple example of this is flicking a booger off your finger (the spring twanger) where the viscosity and stickiness can dictate success or failure to launch the projectile in a particular direction and hit the target in the intended location. Groups....forget it! Especially without a good rest.
The math involved in the calculations is expansive, and would have given Albert Einstein indigestion or worse. Where is Stephen Hawking when we need him most?
My math is VWF + HWF + TTWF + TSTT = 100% BS
