Finding "pressure nodes" using QL - better SD/ES?

[SWE_Patrik]

So iv´e just completed a fairly extensive load development for my 6.5CM (new cartridge for me) and i observed something that peaked my interest and i decided to test it further.

I found that my ES/SD on Three different occasions were the best by far around the same theoretical PSI presented with QuickLoad. The kicker here is that the chargeweight was different each time. How? well QL takes into account several things when calculating max PSI such as:
- case capacity
- temperature
- seating depth (affects case capacity)
- initial starting PSI based on seating into the lands or jumping it.

All these parameters were different because i was fireforming brass the first time (less WCC) and one time i seated into lands the next jumping it etc etc.
As a note accuracy also followed as the best for these "pressure nodes"

Now this my very well be a fluke and im reading to much into it and there are so many other factors here and the data i have is a Little slim to support it for now. Also i can´t Think of a logical explanation for the observation, could there by such a thing as "pressure nodes" that correlates to very good ES/SD ?

So i thought i´d ask you guys!
1. Have you seen a similar observation using QL?
2. Can someone smarter than me corroberate or dismiss the theory?

Either way i´m gonna test the theory onwards and load up the same bullet/poweder combo using completely different brass and see if i get the same V0, low ES/SD when QL says i´m hitting the same QL as Before.

Cheers!
Patrik, Sweden

 

[spife7980]

http://www.the-long-family.com/OBT_paper.htm

 

[SWE_Patrik]

Yeah that might have some bearing on this but the article doesn´t really talk about "good" velocities ie low SD/ES as a result of different pressure nodes or OBT nodes right?

 

[Milo 2.5]

Yeah that might have some bearing on this but the article doesn´t really talk about "good" velocities ie low SD/ES as a result of different pressure nodes or OBT nodes right?

No, it really doesn't, but that is what the OBT is, giving you predicted pressure nodes where if in them group size and number variations should shrink at the same time. There is good info on load dev, OCW, Ladders, OBT, chrono utilizations, instead of following one to the death, skim the goodies from each. As your load starts to form, neck tension and seat depth can fine tune a good load into a great one.