A Discussion With CCI Tech Support

C

COSteve

New member
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.
 
I heard about this a couple years ago and now just buy the SR primers for my 9mm, 45ACP, 223 and 7.62x39 small pockets. Works great.

If only I could do this with large primers. Sure would simplify things.
 
I am so glad someone confirmed that. thanks, and kudo's for her for letting the trith out, she'll likely be reprimanded. I have been using mag primers for everything for a couple years now, since never experiencing a fluctuation or a piercing, I assumed the difference had to be very minimal. I have a feeling you little OP there is going to be tossed around the internet more than a ........I should just stop there. but cool. I only still use rifle primers for .223 because I really like how hot the Tula KV-223 are, other than that I use mag pistol when I can. I also use spp sometimes with powderpuffs, but only what I have left in the stash, I haven't bought any in a long time.
 
So this means I can use small rifle primers for all small pistol and rifle reloads without any negative side effects?
 
Jojo...CCI primers, yes. They are a tad 'hotter' than small pistol so adjust your powder loads accordingly.

Just to be clear folks... this applies to CCI primers.
 
They can be used, but that's not the same as saying they'll be best. A lot of benchrest shooters look for extra mild primers. In particular, a lot of folks shooting the .22 Hornet have trouble with high velocity spread with regular SR primers. We think it's because of the small case capacity and low grip strength from the thin neck allowing many standard primers to start unseating the bullet before the powder can build enough pressure to do it, and not doing this uniformly. So mild small pistol primers are often sought out for this round.


Steve,

Thanks for reporting that information.

I've called CCI before inquiring about their magnum vs. military-sensitivity spec rifle primers and had them give me that same impossible 3 microgram number. The large primers I've measured before and after firing have usually lost about .4-.5 grains of weight. Some of that is the paper "foil", but since Remington boasts of controlling their priming charge to ±0.01 grains (about 650 micrograms) I expect about 0.3-0.45 grains (20-30 milligrams) is pretty typical mix quantity. Small primers will have less, but not 10,000 times less. The lead styphnate seems to be about 10% of the mixture, so, possibly, they have about 3 milligrams of lead styphnate in the mix and she is simply misreading mg as μg.
 
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