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View Full Version : Conversation With CCI Tech About SPM vs SR Primers


COSteve
July 22, 2010, 11:25 AM
I posted this on another site last summer and forgot about it. I happened to find my MSWord document of it so I thought I'd share. This is from a conversation on June 14, 2009 with CCI's tech dept.

I called not to complain about availability, but rather 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. BTW, She mentioned that she had worked there 38 yrs and never seen anything even close to this kind of demand.

Then she said that they can produce 3 million primer per day flat out (which they are currently running) but have currently over 1 Billion back ordered. Unfortunately, that means that if all new orders stopped completely today. Everything; ammo, gov't, and component, it would take almost a year running flat out to catch up.

Anyway, 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).

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 there only bought rifle primers and used them for all their reloading, magnum or not. The only exception being for custom pistols where the thicker rifle cup contributed to misfires, which she said only occurred in custom race pistols.

Doodlebugger45
July 22, 2010, 12:02 PM
Very good work and I appreciate the info! It's something I have wondered about myself in loading for my 454 Casull. The reloading manuals make a big deal about using SR primers, but now I see that SPM primers are identical. I only wish you would have asked about SR BR and SRM primers. I noticed that I had quite a bit of unburned powder in the .454 when I used IMR 4227. I switched to SRM and it seems to have helped that issue. But these days, you can't always get what you want in primers so it's good to know exactly what the alternatives are.

I also have spoken with the techinical people at CCI and it's really a pleasure to find out what they know.

Brian Pfleuger
July 22, 2010, 12:53 PM
Wow. That's really helpful to know. Thanks Steve.:)

Krieger9
July 22, 2010, 03:14 PM
+1 thanks.

Tasty data.

Unclenick
July 22, 2010, 03:27 PM
Good to know. I am also surprised to hear the standard pistol primer is slightly shorter. I always thought all small primers had the same external dimensions, and the only large pistol and rifle were different. Perhaps they're trying to protect the thinner cup from piercing?

tom_pixel
July 24, 2010, 05:20 PM
Good to know this as I was about to call CCI tomorrow , as I am getting back into reloading 9mm and 38 S&W. Local gun supply handed me a box of CCI 400 primers ah ok but after reading my new Speer reloading book they reccomend the 500. I wasn't sure if there was a difference in dia or ?
...tom

Jim Watson
July 24, 2010, 05:38 PM
The only exception being for custom pistols where the thicker rifle cup contributed to misfires, which she said only occurred in custom race pistols.

Quite the opposite of my perception. A lot of .38 Super "raceguns" get loaded with small rifle primers to disguise the signs of high pressure from the overloads commonly used to make Major Power Factor.

Unclenick
July 24, 2010, 05:58 PM
Probably was talking about trigger and action jobs done by using weaker mainsprings. Back in the 80's, I put a Wolff spring set in a Dan Wesson revolver. It lightened the DA significantly, but it also misfired CCI primers routinely, afterward. It could ignite Federals successfully, but eventually I put the original mainspring back. I just didn't trust it, otherwise.

Jim Watson
July 24, 2010, 07:43 PM
19 lb 1911 mainspring (23 GI) fires small rifle primers in my Colt 9mm.
Revolvers are more sensitive.

TXGunNut
July 24, 2010, 08:16 PM
She may have been thinking about PPC revolvers. Most have a very light hammer strike and can't use CCI primers, usually WW or Federal. Been out of that game for awhile, things may have changed.
Cool conversation, sounds like she really knows her stuff. Thanks for passing it on.

draggon
July 24, 2010, 08:35 PM
So the SPM and the SR are identical primers. just labelled differently for marketing?

tom_pixel
July 27, 2010, 09:28 PM
Local shop gave me 400 Hmm book says use 500 , so wrote Linda at CCI and her response was for my 9mm :
CCI 400 primers are not the correct primer for 9mm Luger. They are a
small 'rifle' primer. The bottom thickness is thicker on a rifle primer, they are a hotter primer and are also taller in size than a pistol primer.

The correct primer is a CCI 500, Small Pistol primer.


Linda Olin
CCI/Speer Technical Services
2299 Snake River Ave.
Lewiston, ID 83501

fyi ....te

draggon
July 28, 2010, 04:20 AM
We've agreed that the SP (500) and SR (400) are different but the question was whether the SR (400) and SPM (550) are identical?

Sport45
July 28, 2010, 05:36 AM
question was whether the SR (400) and SPM (550) are identical?

It sounds to me like the CCI tech is saying they are the same.

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.

Of course you can't believe everything you hear from the manufacturer. Just ask around here if WW231 is the same as HP38 or if WW296 is the same as H-110. ;)

draggon
July 28, 2010, 06:51 AM
That was my take on it.

escard
August 4, 2010, 02:10 AM
the technican from CCi says "primer cups of #550 and #400 are identical"!
But how would the tech-rep explain the fact that I have a S&W that does in DA-mode fire #550 primed cartridges steadily (100 of 100) while the same loading, yet primed with the cci #400 results in one or two misfire(s) per cylinder?? That means 1 out of six/2 out of six are badfirings/misfirings !!!
I do not give anything on such "technical help" because I did my own testing (in reality, not theory).....

WESHOOT2
August 4, 2010, 09:23 AM
I use primers this way: What works best?
Is it RELIABLE?

Is the load MORE or LESS accurate?

Are ballistics immproved?

I rarely (I mean real rare) use Small Rifle primers in my pistol loads; I have many, but rarely use them.

resugun
August 4, 2010, 10:11 AM
Originally posted by Unclenick

I put a Wolff spring set in a Dan Wesson revolver. It lightened the DA significantly, but it also misfired CCI primers routinely, afterward. It could ignite Federals successfully, but eventually I put the original mainspring back. I just didn't trust it, otherwise.


I installed a Wolff kit in my Dan Wesson as well and routinely fire .180 grain loads with CCI primers without ever having a misfire.

Unclenick
August 4, 2010, 01:04 PM
Mine was in the 1980's. If yours is more recent, they may have remedied the problem.