Actual chamber pressures for standard Vs magnum primers

[JeepsAndGuns]

I have often wondered if any place that has the ability to read/check/measure actual chamber pressures of a cartridge has ever done a test comparing standard and magnum primers.
I have always heard the story (reduce the charge by 1 grain if switching to magnum primers). But I have often wondered about what and how much it can/will change the actual chamber pressures.
For example, load a specific round with x bullet and y charge of powder, using a standard primer. Then load the exact same (bullet, seating depth, power and charge) but then switch to a magnum primer and see how much the chamber pressure changes.

I suppose a probably less accurate and less scientific way could be to use a chrono and load a conservative load, get a average fps, then switch to a magnum primers and see how much the fps changes.

[Stumpkiller]

Western Powders did a study of standard vs. magnum primers for the pressure increase (in a .338 Lapua case it increased 12.7% to 18%(!) depending on brand). They also compared differences in temperature: 1.8% when going from 70F to 140F.

I don't know if it is considered rude here to link to other forums - but here is the Western Powders blog page link.

http://blog.westernpowders.com/2016/01/primers-and-pressure/

[celltech]

For what it's worth the GRT loading tool shows a 1595psi increase for magnum rifle primers...

[JeepsAndGuns]

Western Powders did a study of standard vs. magnum primers for the pressure increase (in a .338 Lapua case it increased 12.7% to 18%(!) depending on brand). They also compared differences in temperature: 1.8% when going from 70F to 140F.

I don't know if it is considered rude here to link to other forums - but here is the Western Powders blog page link.

http://blog.westernpowders.com/2016/01/primers-and-pressure/


That's the type of test i was looking for, but too bad they did not test other calibers. I would love to see the effects of pressure on some smaller calibers. Maybe 308 or 30-06. Then some small primers like 223. As well as pistols such as 44 mag and 357 mag.
I am probably asking too much.

[Stumpkiller]

I'm almost positive I have run across one on the .357 Magnum. I'll have to back-track. Last fall I picked up a couple pounds of VV N-110 for use in my 10" Contender and many of the .357 Mag loads use a standard primer; and I was hunting around to see what loads with a magnum primer might compare.

Might be in the Marvin Stuart "Book" on the .357 Mag. (and well worth checking out (it's free!) if you haven't seen this before).

http://marvinstuart.com/firearm/Manuals/Reloading/Caliber%20Specific%20Load%20Data/Complete%20Reloading%20Manual%20for%20the%20357%20 Magnum.pdf

[243winxb]

Search https://discover.dtic.mil/ And https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079