cci sp,spm,sr specs, or interchangeability

[mapper]

I found this in my travels,

But haven't done it personally, other than srm have a thicker cup than the others and didn't work out well when I tried them in a pistol, imagine that..

There is another thread somewhere in this section giving dimensions and cup thickness of primers if you want to search for it as a companion to this one and compare the data.

https://forum.capitalcitygunforum.co...-Primers-Right

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These are my notes from a conversation on June 14, 2009 with CCI's tech dept.

I called to discuss the technical differences between their primer types. I was put in touch with one of their tech reps who was very happy to discuss their primers. She mentioned that she had worked there for 38 yrs and was glad I wasn't calling to complain about the current primer shortage. I was asking about the cup thickness, formula differences, and formula amount differences between their #500 (SP), #550 (SPM), and #400 (SR). She had me hold a minute to get the detail specs up on her screen and this is what she said.

Cup thickness: The #500 has a thinner cup than either the #550 or #400, however, both the #550 and #400 have the same cup dimensions (including thickness) and material hardness (same brass).

Flash powder formula: All three sizes use the same formula for the flash powder.

Flash powder amount: The #500 has a slightly smaller amount (3 micrograms) than the #550 or #400 which both have the same amount.

I asked if the SR primers could be used as an acceptable substitute for the SPM primers. She compared the #550 and #400 and then replied that yes, they appeared to have the same specs, same dimensions, same cup thickness, same formula, and same amount of flash powder. She even noted that the SPM primers were slightly taller than the SP primers and were spec'd the same dimensions as the #400.

I asked if she knew any reason not to just use SR primers for both magnum pistol and rifle applications based upon that information and she said that many employees who worked there only bought rifle primers and used them for all their reloading, magnum or not. They just started at the minimum and worked up their loads. The only exception being for custom pistols where the thicker rifle and pistol magnum cup contributed to misfires, which she said only occurred in custom race pistols.
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[seadog]

Thanks for sharing that awesome bit of information.