I am far from an expert on this subject, the below is just my understanding of the procedure I reference below. I'm interested in hearing what some of the more experienced people here have to say about it.
I tried using this OCW process using the instructions I found here: http://www.ocwreloading.com/about.html
to develop a load for a 6.5 creedmoor and a 30-06.
It got my interest based on the following claims:
- Determine OCW with minimal number of rounds
- Improved (less) temperature sensitivity
- 100y shooting range (10 minutes away)
So after reading the manual several times, I decided to "trust the process", load some ammo and go to the range. I did the 6.5 creedmoor first, 129 nosler ABLR, H4350. After the first trip to the range, I came home with a pattern of targets that looked similar to yours. My conclusion was that I didn't go to a high enough charge weight (I don't know what the max is for your powder/bullet combo). So, I loaded a whole new batch up to a higher charge weight and went back to the range. After shooting, the results looked more complete, and chose what appeared to be the OCW according to the process, and then started to adjust seating depth using the charge weight I had identified.
Getting the right seating depth took a while, but I was finally able to make 3 holes touch on rounds 96, 97, and 98... (fired round robin)
I wasn't impressed with how many rounds it took, but part of that can surely be contributed to my lack of experience...
As for the temperature stability claims, I loaded these in Feb, and still have about 40 rounds to try out this summer. We will see...
Going to longer range, I have a 16" plate at the deer lease that I was able hit 3/3 at 600y (~2.7 MOA) I know that's not outstanding proof, but ya gotta work with what you got sometimes...
After going thru the same process for the 30-06. I came to the conclusion that I need to order some Lapua brass... and/or get an annealing machine, the brass was work hardening fast, believe it was giving me neck tension problems.
That being said, if I were to "trust the process" with the data you've given, it looks like either 40.5, 42. Not sure what the max is, but it would be interesting to see where 42.3 would end up?
I like charts, so I plotted the data you provided, so it's easier (for me at least) to see where the "flat" spots are.
Like I said at the beginning, I am not an expert at this, and this was just my interpretation of "the process" I would like to hear from others here if there is any merit to this process? Or was I just drinking the cool-aid?