Article - Primers And Pressure

Notes and Research:
(As a note of interest, small pistol primers are .017" thick and large pistol primers are .020" thick.)

Another factor which determines the strength of a primer cup is the work hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened. Manufacturers specify to their brass suppliers the hardness of brass desired. I was not able to test primer hardness, but an educated guess says that a primer manufacturer would choose a harder brass in order to keep material thickness down and reduce costs.[http://smith-wessonforum.com/reloading/72058-ok-what-difference-between-small-pistol-small-rifle-primers.html]

CCI Primer Info.: Note #7 is an old manual for SPEER

Primer Cross reference chart

My Micrometer Readings for these primers height are: 

    Federal #205 Small Rifle Primer = 2.925mm (0.11515748 inch); 

    CCI #500 Small Pistol Primer = 2.985mm (0.11751969 inch)