Load development method : Optimal Charge Weight

I just question that nodes exist, I won't say they don't exist - the testing to prove that would be never ending

I pick a bullet I want to use, knock about 5% off the max load and load up ten rounds each with a few different powders (anywhere from 3 to 10 types). Seating depth will be at least .030 off lands, .050 off for monometals (or as long as mag lengths allow)

I'll fire the loads, in 3-5 round strings depending on barrel contour and intended use (hunting vs target) at 200 meters. Ending up with ten round group, which is measured for group size, mean radius. I will adjust the charge weight up or down, depending on what I am looking for. I'll retest the best results with 15 round groups, eventually what works the best will rise to the top
Well you could reverse engineer to find out.
Take your good 10 round choice and compare it to a slightly different powder charge on either side. Shoot at 200 or farther. When I fine tune powder it’s only in one tenth steps.

Then you can also compare seating depth in the same way. I rough test in 3 thousand’s and fine tune in one thousand’s steps on either side.
 
Well you could reverse engineer to find out.
Take your good 10 round choice and compare it to a slightly different powder charge on either side. Shoot at 200 or farther. When I fine tune powder it’s only in one tenth steps.

Then you can also compare seating depth in the same way. I rough test in 3 thousand’s and fine tune in one thousand’s steps on either side.

This is where the round counts stack up big time in load development. If you do it in ten round groups, which are much more statistically valid samples than 3 or 5 shots, testing powder charge steps of 0.1gr, you'd fire off 70 rounds right there (base line 26.10grs, testing 26.0, 25.9, 25.8 & 26.2, 26.3, 26.4grs) - now we find 25.9grs gave the best group size and/or mean radius. Now testing seating depths, going from the base line 1.892" CBTO, we test .003/.006/.009/.012 shorter, and longer - for 90 rounds of test loads, bringing load fine tuning round count to 160 rounds

Finer seating depth tuning of .001 on either side of the best jump from the first test, brings load development fine tune round testing to 180 rounds

On ten shot samples of the exact same load, you'll see variations of results of 30-40% smaller, and 30-40% larger from the average. If a guy did super in depth testing, resulted in an average 0.75moa ten shot group, you could fire a bunch more with the exact same ammo and see groups from 0.5moa to 1.0moa

3 shot samples vary 60-70%, which gives us the "node" results on target. 0.5moa average group will print results from .18 (node!) to 0.83moa with the exact same ammo.

So do nodes exist? I hope to get out later today and do my seating depth test for OCW 2.0 to shed a bit more info on this load development technique

How did you settle on 34thou off the lands?

It put .224" of bullet shank below the case mouth. I generally don't like to seat bullets closer to the lands than .030 anyway, so it worked out. SAAMI 223 Rem overall length is 2.260", these test loads were loaded at 2.291"
 
I was talking about 10 round groups on either side when you think you are done with your load to confirm.

F class shooters hope for 5” groups at 1000. They do not shoot their barrels out with mega round load development. Yet they somehow manage to be close. They don’t get hung up with stats. We should not be hung up on it either.
 

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