Small Rifle Primers in Small Pistol

[avogunner]

With our current primer “shortage”, there’s been some discussion recently about the use of Small Rifle primers in the place of Small Pistol. Honestly, I had tried it before, with satisfactory results, but I’d never chronographed the loads to see if the rifle primers make a difference. So, for a test I put together 50 rounds of .357 Mag for testing with my S&W 66 (4” bbl)

- PPU brass
- Lyman 358156 GC
- 10.8 gr of 2400 (thrown by a Pacific Pistol Powder Measure which uses bushings like a MEC)
- 10 rounds each with the following primers; Win SPM, FIO SR, Win SR, Rem 6 1/2 SR, CCI-400

I didn’t test for accuracy, just velocity, and they ended up grouping similar at 10yds but here’s the 10 round average velocity as recorded by my Chrony Beta:

Win SPM (Small Pistol Mag used as the control) – AVG 1140 fps
Fiocchi SR – AVG 1084 fps
Win SR – AVG 1186 fps
Rem 6 ½ SR – AVG 1117 fps
CCI-400 – AVG 1155 fps

I've read that SPM and SR have the same brisance and I would tend to believe it as the velocity was similar for all primers. Also, none of the brass showed any signs of excessive pressure, and as harder primer cup was a concern, all fired normally - none required a second strike of the hammer (my pistol has the stock mainspring).

Yes, this is totally unscientific but it was interesting (at least to me). I’m perfectly comfortable repeating this test with other small pistol calibers (.38 special, 9mm, and .40 S&W) and would suspect similar results. Of course, starting at minimum loads and working up is always sound advice but it does seem that if the need arises, substituting SR for SP isn’t that much of a problem.
Semper Fi.

[BigAlofPa.]

Thanks for the post. I loaded some 357's with SRP. Didn't get out to test them yet.

[CoolHandMoss]

Thanks for posting that. I have been considering loading some .357 with srp myself.

[hoodat]

I'd also like to thank you for your post, and the time your research took. Who among us isn't starting to evaluate our options at this point.? jd

[Goofy]

Have done so with several cartridges over the last two years with no downside. In comparison I find with the same charge I can expect a mild increase in velocity and small velocity spreads.

[la5676]

I would not think the issue to be so much in the brissance level of either, but the cup thickness of the rifle primer vs the pistol primer. I always understood a rifle primer was made with a thicker cup to withstand the floating firing pin of most semi-auto rifles. Striker fired pistols have a hard time setting those harder cups off. Heck, I know some guys that have issues with pistol primers with weak firing pin springs. Hammer fired pistols can normally handle the SRPs just fine.

[Goofy]

Should add that my referenced experience above was with CCI primers of both styles. I have noted significant velocity changes with same style of different brands.

[dougader]

I wonder what the difference would be between SP and SPM primers.

My old standard Blue Dot load from Speer 11 was not max (140 gr Sierra JHC over 13.5 gr Hercules BD), but we can see from more current data that it is NOW considered over max. My load then used CCI 500 SP standard primers.

Brain fade... one time I loaded up 50 rounds of my usual load with CCI 550 SPM primers. The result: flattened primers and sticky case extraction. I looked at the box to read the load and was shocked to see that I used the wrong primers... went home and pulled the remaining 44 rounds.

I don't see a problem with substituting SR primers as long as you're not already running a maximum load, in which I case I would advise backing off the powder charge a bit.

[Walks]

I have a brick of OLD Federal #200 that are marked on the end flap; Small Rifle & High Velocity Pistol. And I've used them for .357Mag loads with Max W296 and IMR4227.

[CraigOK]

Someone posted a video about this, wish I had saved the link. The guy was an ammo manufacturer, but they would make ammo from your components that you sent in. He loaded up same load with SP, SPM, SR primers and velocities were basically the same. He said the difference is cup hardness/thickness. Same priming compound but your pistol may not be able to set off the SR primer. Hope that helps
Found the video
Watch "Are Small Pistol Magnum & Small Rifle Primers Safe in 9mm?" on YouTube
https://youtu.be/NGVRGsoOr6k

[bluejay75]

I don’t buy SPPs. I only have Winchester SRPs stocked. Never had a problem. I exceeded published Max once and pierced primers but that’s on me.

They work great even with 38 special loads. Keeps my components simple.

[flyingmonkey35]

I have loaded and shot suscusfuly. Sp in .223 mouse fart / gallery loads.

4 grains of CBI 55 grain cast pc lee boolit NO gas check. Small pistol primer.

Shot out of a wenchester bolt action .223

That's a tack driver.





Sent from my SM-G960U using Tapatalk

[beagle]

I asked this question about three months ago. Since then, I have been subbing SR for SP in .38 and .357 loads with no problems. I have steered clear of loading them in 9mm loads due to the small case capacity. So far, it's worked all right for me./beagle

[dondiego]

I don’t buy SPPs. I only have Winchester SRPs stocked. Never had a problem. I exceeded published Max once and pierced primers but that’s on me.

They work great even with 38 special loads. Keeps my components simple.

So, are you saying that you use Small Rifle Primers in all of your handgun loads? It's not clear to me.

[Evoken]

I have been using fed sr (210?) In 357 and have had great results. I have plenty of rem 1 1/2 for 9mm and 38spl, so good there. Probably gonna try the fed and cci sr in 40s&w soon just to see how it will fair.
Ken

[Larry Gibson]

I've 100 [ten 10 shot tests, each with a different primer] of 357 magnums loaded with 6 gr of Alliant Unique under a 358156 (162) gr ready for pressure testing. Just waiting for a decent day.

The ten different primers to be tested are;

Small pistol primers:

CCI 500
Federal 100
WSP
CCI 550

Small rifle primers:

Remington 7 1/2
CCI 400
WSR
Federal 205 magnum
CCI 450

The test results should give a better understanding of any potential hazards.

[CraigOK]

Larry did you see that video? Do you see anything with his equipment and methods you disagree with?
Itll be nice to see your results too, thanks for putting in the time and effort

[Larry Gibson]

Yes, I watched the video several times. I believe I posted my comments on the thread it was on.

[la5676]

Someone posted a video about this, wish I had saved the link. The guy was an ammo manufacturer, but they would make ammo from your components that you sent in. He loaded up same load with SP, SPM, SR primers and velocities were basically the same. He said the difference is cup hardness/thickness. Same priming compound but your pistol may not be able to set off the SR primer. Hope that helps
Found the video
Watch "Are Small Pistol Magnum & Small Rifle Primers Safe in 9mm?" on YouTube
https://youtu.be/NGVRGsoOr6k

I think that's what I said in post #6 isn't it. And pretty much what beagle is implying in post #13, as most 38/357s are gonna be hammer fired pistols and likely will have no issues with SRPs.

[relics6165]

I was visiting with my son the other day, this topic came up, his reply was that he uses SRP in everything, pistol and rifle.

[BrutalAB]

Ive got the opposite problem, got more spm than i do sr and sp combined.

Would of course like to have more of each. But i suppose i can make do until the market returns to normal.

[dougader]

I've 100 [ten 10 shot tests, each with a different primer] of 357 magnums loaded with 6 gr of Alliant Unique under a 358156 (162) gr ready for pressure testing. Just waiting for a decent day.

The ten different primers to be tested are;

Small pistol primers:

CCI 500
Federal 100
WSP
CCI 550

Small rifle primers:

Remington 7 1/2
CCI 400
WSR
Federal 205 magnum
CCI 450

The test results should give a better understanding of any potential hazards.

This is what is important, pressure... not so much velocity. I recall reading, maybe in a Speer manual, that using a magnum primer in some powders (like AA #9) would only raise pressure, NOT velocity.

In my post above, I noticed no difference in firing those 6 Blue Dot loads, but the sticky case extraction woke me up, as did the flattened primers.

[Yooper003]

I have seen it posted several times & at least 2 people have said it came right from CCI, that with CCI primers SPM & SR are the same. I have been using them as such.

[Whole Bunches]

Used to own a MP40. CCI 500 were giving pierced primers. Load was not hot. Bullseye was the powder. Substituted CCI 400. No more pierced primers and the same velocity. Final corrective action was installing another smoother faced firing pin. I then went back to using the 500 primers.

My Glock would not always pop the 400 primers.