It's called Mohr's Circle, but it's been 30+ years since I've even thought about one, much less did any figuring about it.

Clark,

You trying to make us oldtimers (Alzheimers) feel bad?

Mike Eberlein

Clark Magnuson wrote:

I can calculate the compression and tension, but don't know how they add.

The 10 mm pistol cartridge has a primer pocket ~.208 and an extractor
groove ~.338".
The makes the primer pocket walls thickness = [ .338-.208"]/2= .065" thick
Neglecting the primer thickness and the time delay of the flash hole,
the thin wall hoop stress of the primer pocket wall is then
S [tension] = P [chamber pressure] .208/[ .338-.208"] = 1.6 P

The inside diameter of the case mouth is .408".
Neglecting case to chamber friction, the bolt thrust is then:
F [bolt thrust] = P [chamber pressure] pi A [inside case area] squared =
P pi [.408"/2] [.408"/2] = .13P
The stress on the primer pocket walls is then
S [compression] = F [bolt thrust] /A [ longitudinal cross sectional area
of walls] = .13P/ [pi [ .408/2] [ .408/2] - pi[ .208/2][ .208/2]] = 1.34 P

The 10 mm cartridge is rated for 37.5 kpsi chamber pressure so:
primer pocket wall tension = 1.6 P = 1.6 37.5 kpsi = 60 kpsi
primer pocket wall compression = 1.3 P = 1.3 37.5 kpsi = 50 kpsi

There must be a way for 60 kpsi tension and 50 kpsi compression at 90
degrees from each other to be added and compared to the yield point of
hardened brass.
TIA

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.