[3blade]

I read through it a few times, I get what you are doing and applaud you for the practice. here's some thoughts...

-You need to be shooting true lasered horizontal distance, on calm days, in order to collect data. Any up/down/wind/variable temp data is irrelevant for now.
-Your version of determining point of aim is wayyy too complex for hunting and imprecise for target shooting. you are going to run into problems at uneven yardages and in field conditions. There is a reason for mils or moa turrets, cronos and calculators. Right now you're flinging lead with an educated guess, which is fun, but won't prove much.
-I'd bet that the ES of your ammo may account for variations at 500
-past 300 is where things go wonky for everyone. That's where variables start showing up. You've learned and recognized this first hand, which is good.

You first need to establish the consistancy of your ammo (chronograph). Then, if its acceptable, come up with a consistent solution for picking a point of aim (id go with 1/4 MOA turrets, its easiest for me to think about). Then plug some numbers into a calculator. Then shoot your rifle a bunch in calm conditions and consistent temperatures, to make sure your actual results match your calculated results. Once you have good accuracy and precision (good groups hitting where you aimed) at 300, 350, 400 and out at 25 yard increments, then redo your test and I'd bet you will be much happier with the results. Horse must go before cart.