I read those articles, but seeing as they don't go into how brisance effects the burn of the powder directly, I will elaborate.
I have a Pressure Trace II system which takes raw data from a piezo crystal glued to the barrel about midway in the chamber in most rifles, some differ as there is no room to get it near the middle for various reasons.
CIP and SAAMI take their readings from very different points on the case and in the burn of the powder.
Now, brisance in regard to HOW a powder burns, does 2 things essentially. Firstly, the primer flash intensity, pressurises the powder column and forces the entire powder column up towards the bullet base.
This also pressurises the entire case, without pressure, nitrocellulose is difficult to ignite, hence why primers are so powerful.
The second thing it does is influences the start pressure of the burn. A smooth gentle curve is often the one that gives the best accuracy. A harsh one will not be consistent and one that is too low will not ignite the powder enough and will be more erratic than one that is too harsh.
Over the Pressure Trace it is pretty obvious which primer and powder combo are going to match up early on in the testing…
In both my 22-250AI and 6.5x47 Lapua using SRP brass, the smaller flash hole as well, has a curve under MAP that is totally different to cases using LRP brass.
It also changes the velocity with the same loads if tested side by side. I can't test LRP brass for the 6.5x47 cuz I don't have any, but in the 22-250, I have both SRP & LRP brass.
According to my tests, switching from a standard primer to a magnum primer, or even brands, can raise pressure by 6,000psi to over 10,000psi at MAP.
Regarding start pressure, it can change by 4-5,000psi just based on brand alone, and switching from standard to magnum is about the same as going from a cold primer to a hot primer.
Winchester primers across the board, both SRP & LRP, whether standard or magnum are considerably hotter and raise start pressure very well on a mediocre load using other powders.
My 25-06's all but one love WLRM primers, the other, my Sendero loves 210's Match primers.
Oh, and testing Match primers to other primers, I could not see a difference with any of them except with BR4's, they were gentler than CCI 400's.
I have no conclusions regarding primer cup thickness, just that some pierce easier than others and the only pierced primer I ever had was with7 or 7 1/2 (I think) in a 17 Rem about 25 years ago, I didn't realise when I bought them there was a difference. Every single one pierced and etched my firing pin hole.
As long as you work up when switching to a magnum primer or even switching brands and testing, nothing bad can happen really.
Cheers.
