Small Pistol Magnum Primers in .45acp SPP Brass discussion

[metricmonkeywrench]

My intent is not to start a war, go down in flames, called every name in the book or hear the tales from your father’s brother’s nephew’s cousin’s former roommate about mushroom cloud expedited disassembly events. My goal remains to utilize the components I have available on hand to the maximum extent safely. I can obviously decide to put it all back on the shelf and not peruse this venture any further.

Here’s the basic question/theory- Are Small Pistol Magnum primers when used in .45acp SPP brass more or less equal in operation of standard Large Pistol primers in normal .45acp LP brass? I use the term “operation” loosely, pick your method of measurement- Brisance, heat, pressure and so on. This is one of those cases where industry has created a bridge where the absolutes of what normally goes with what does not seem to apply.

On my bench currently is a sleeve of Winchester Small Pistol Magnum (WSPM) Primers, a box of Blazer SMALL PISTOL PRIMER brass, a Lb. of Bullseye (though I have Red Dot and 700x and a couple others in the wings) and a pile of lubed up 542374 225g LRN bullets. I searched out and re-read Larry Gibson’s excellent posts/discussions and a couple others on using magnum primers in 9mm and 38 Special. But none seem to directly apply the combination I’m looking at.

I’m not even sure what Federal uses in these cases as standard primers, or are they the new Non Toxic type that has not been mapped out yet for operational parameters compared to other primers. The last couple of times out for this brass has been with Federal F200 Small Rifle Primers which I have been using in all my pistol calibers until exhausted (Darn shortages and high prices, but that’s a different post) with no issues.

Constructive thoughts?

[JimB..]

Is the question “can I load 45acp with small magnum primers?
The answer to that is “yes.”

Can you do it with Bullseye?
Also yes.

Can you safely use data for a standard LPP?
Probably, but I would work up a new load because it’s good practice to do so.

[JonB_in_Glencoe]

Are Small Pistol Magnum primers when used in .45acp SPP brass more or less equal in operation of standard Large Pistol primers in normal .45acp LP brass?

SNIP>>>

Probably. But that is a question you have to answer for yourself.
.
I've seen articles that did tests and found that different brands have different Brisance.
That would be a factor.
.
Mag primers are typically spec'd for
1. hard to ignite powders
2. Large capacity cartridges
-more so important when a application includes both.
3. lastly, and somewhat controversial, ammo for use in extreme cold weather.
.
Now, as I understand it, Mag primers aren't really hotter, they burn longer, which will build up more heat, so they are kind of hotter, but I like to use the term stronger.
.
One thing I've heard, that 'can' happen when using a Mag primer in a low power pistol cartridge, when one isn't needed, is the stronger primer pushes the bullet out a little bit, then may stop briefly [think micro-second], then the powder burn pushes it. You probably heard of S.E.E. and that is one theory that no one has proved to me. Can it blow up a gun? I don't know?
.
Those are some things to think about, when trying to answer your own question.
.
Here is some info about the new Federal compound, and info about primers in general, that also might help you answer your own question.
https://www.outdoorlife.com/cartridg...MPID=ene070218

[TD1886]

For the fact that a magnum small pistol primer doesn't hold as much primer compound as a larger pistol primer would lead me to believe they are not equal.

[gunwonk]

For the fact that a magnum small pistol primer doesn't hold as much primer compound as a larger pistol primer would lead me to believe they are not equal.

Dunno about how much priming compound, but here's a table that seems to say a magnum SPP has more energy than a non-magnum LPP. I'm not certain where I got the table, but I suspect it's from an older Speer reloading manual.

[TD1886]

Dunno about how much priming compound, but here's a table that seems to say a magnum SPP has more energy than a non-magnum LPP. I'm not certain where I got the table, but I suspect it's from an older Speer reloading manual.

You may have gotten from a Speer manual, but it appears to be CCI test. Yeah it does beat, but not by much. Like I said the 45acp doesn't need more primer for the minute amount of powder it holds. Don't tell me it has lots of capacity, but not when the bullet is seated in it.

[Ed_Shot]

Dug out my log book, back in 2013 there was discussion here about this same topic. Out of curiosity I did a "very limited" test of LP vs. SPM primers in 45 ACP brass using 452374 lubed with WL 2500+ over Promo 4.5 gr at COAL 1.272. The primers were CCI 300's and CCI 550's. My chrony showed a whooping difference of 2 FPS average velocity between LP and SPM for this load. As I recall from the thread at the time (I can't find it) members found that SP primers gave lower velocities than LP primers for a given load "all other components being equal" while SPM primers generally matched the performance of LP primers in 45 ACP loads.

I do not trust generalizations. The best advice I got from Mr. Gibson is that "Your chrony is your friend." Start low and work up.

[metricmonkeywrench]

All, Thanks for the input so far especially the CCI table from gunwonk I'm starting to feel more confidence in proceeding on the intended path. What I may do is a limited ladder (yes, starting low of course) with half the box using my SR F200's and the other half WSPM's across the Chrono. I may also have a short box of standard SPP that may be added to the mix for a "baseline".

Based on the CCI table, at least in their case, Small Pistol Magnums appear to fall in between Large Pistol and Large Rifle primers which are often substituted when the standard LP primers are not available. I remember reading here somewhere that there are a bunch of folks who simply converted over to small and large rifle primers to simplify their shelf stock/buying and adjusted their loads accordingly.

[FullTang]

I load both in .45 Auto, but mostly SP, since my progressive press is set up exclusively for small primers. SPPs definitely have less oomph (I believe that's the technical term) than LPPs, and velocities in identical loads are definitely measurably less with SPPs. MSPPs seem to even things out nicely and get up to the same velocity as LPPs, but not more. I assume that means the pressure is close to the same, but I can't measure that---close enough for me, YMMV. During the shortages, I have also used small rifle primers in pistol cartridges. They are generally considered equivalent to magnum small pistol primers, though it all depends on the brand. Most folks seem to believe that CCI MSP and SRP are the exact same item with different packaging, and that's how they behave in my hands. Some SRPs are harder than others and give me light primer strikes in some of my guns, so that's an issue to consider. I've had the most trouble with Remington SRPs. I've even experimented with Large Rifle Primers in .45 Auto (yes, you do have to squish them in there!), and they seem to work just fine, giving more consistent ignition with lighter loads. I'm sure those raise pressure quite a bit, so I only use them when I'm well under the limits.

[45DUDE]

Some of the large 45acp brass I've picked up are so off center a small primer may not work.

[gunwonk]

You may have gotten from a Speer manual, but it appears to be CCI test.

Speer bought CCI.

[metricmonkeywrench]

Here’s the update and this comes with the usual disclaimers, the results are what I experienced with my components in my pistol and are only a limited set of data and my opinions- Things lined up and the weather cleared up enough for me to get out to the range with the Chronograph to do this test. All rounds were prepped and loaded at the same time with Lyman 452374 RN bullets appropriately aged within 1g in weight, sized to .452 over 4.5g of Bullseye (Lyman load data 4.0-5.0) in twice fired Blazer brass. The only difference was the primers. 20 were primed with Federal 100, 15 with Federal 200 Small Rifle and the last 15 with Winchester Small Pistol Magnum. The 5 extra F100’s were used as barrel fowling rounds to season and warm up the barrel. All were shot from my stock Remington 1911 over a Competition Electronics Chronograph that bluetoothed the shot data to the app on my phone. I used the same 2 magazines and although potentially not necessary loaded only 1 round per magazine to promote some dwell time between each pair of shots and keep the barrel a consistent temp.

Set-up and process hopefully covered enough so on to the results- all after the 5 round barrel warm up and fowling each string was shot in groups of 15 across the chrono. There was no felt change in recoil between any of the strings with no excessive smoke and at the end there was no leading of the barrel. Luckily I had my grandson on hand to chase brass and we were able to capture the first few WSPM shots to examine the brass, though not an absolute indicator there were no signs of any overpressure on the primers/brass and the remainder of the string was fired off. In later examination of the entire box of brass it was near impossible to tell which primer was which. I did use a sharpie on the F200’s primers and they were easily picked out. In hindsight I should have probably marked the WSPM’s

Chrono Results:
Federal 100
Min fps 788
Max fps 819
Spread fps 31
Average fps 801
Std Dev 8

Federal 200
Min fps 782
Max fps 820
Spread fps 38
Average fps 800
Std Dev 9

WSPM
Min fps 805
Max fps 851*
Spread fps 46
Average fps 823
Std Dev 11

*The 14th shot of the WSPM clocked in at the 851 which was surprising and not consistent with the other shots. If I call it an outlier/chrono error and delete the shot the numbers look more consistent with the other shots. And to answer the unavoidable question there were only 15 of each across the chrono I did not have spare rounds to repeat a shot to create a false picture of the results

WSPM without the 851 outlier
Min fps 805
Max fps 831*
Spread fps 26
Average fps 821
Std Dev 8

By the numbers on this it seems that for what I have on hand for this load there is little difference between the standard and small rifle primers. I am about out of the F200’s and may do this again with some WSRP that I have to see if there’s a difference. I’m not expecting any but who knows. I’ve been using the F200’s for quite a while now in all my other pistol loads to extend my small supply of SPP and be able to keep plinking along as alluded to in my first post.

With the WSPM’s I see about a 20 or so FPS jump so there is something there but seems to be within manageable tolerances. The velocity went up and the spread did drop. Wonder if this is a sign of a more consistent burn? I am now confidant enough to move forward and load up some more WSPM’s to see if the outlier was exactly as it seemed.

Oddly enough I have no baseline/ladder chronograph data for the -374 bullet Bullseye load at all. I seem to have landed on 4.7g and tore the center out of a bullseye target and apparently didn’t look any further as by my records that’s what I continually load since I got the mould. I need to go back and run a box of standard large pistol primed -374 LRN bullets with the same load and large pistol primers across the chrono to get a true baseline of a standard load with my components. By the numbers (out of a Lyman #48) I should have only been in the 730fps range.

[Larry Gibson]

"for this load there is little difference between the standard and small rifle primers."

That is essentially correct for that load. However, it isn't because there was no discernable chronograph difference between the primers. There is, in fact, a difference between the primers. That difference did not appear because the load of 4.5 gr Bullseye will generate only so much pressure and, thus, velocity regardless of which primer ignites it. The time/pressure curves with the primers used are close enough that any difference would fall within the variations of all.

Running the test again with a slower more difficult to ignite load of powder such as 7.5 gr of HS6 will probably give difference results. With that load we would see different time/pressure curves along with different rises to peak pressure from the various primers. The recorded velocities would probably reflect those differences.

[metricmonkeywrench]

"for this load there is little difference between the standard and small rifle primers."

That is essentially correct for that load. However, it isn't because there was no discernable chronograph difference between the primers. There is, in fact, a difference between the primers. That difference did not appear because the load of 4.5 gr Bullseye will generate only so much pressure and, thus, velocity regardless of which primer ignites it. The time/pressure curves with the primers used are close enough that any difference would fall within the variations of all..

Thanks for the clarification on the Primers, i was trying to tread lightly on that point and did a bad job of it.

As I alluded to in the original post I read carefully you previous primer tests and for that reason you stated above was exactly why BE was selected as my powder of choice for this endeavor..

[lead chucker]

I have been making my own primers I use the EPH20 recipe and it works. To make a magnum primer its called EPH25 The difference is you ad aluminum powder to the mix. I use 80 to 100 mesh aluminum and you can tell the difference when you shoot a primed empty case when its dark out. It blows shards of burning aluminum into the powder charge to help with slower or more stubborn powders. I could be wrong but this is what i have been told. Not sure if it makes it much more powerful but i believe it gives it a little longer burn. Any body here correct me if im wrong.

[lead chucker]

I believe a spp cup only holds .3 gr priming compound

[bobthenailer]

I used at least 5K fed lp mag primers in the 45 acp with the same load i worked up with fed lp std primer accuracy was darn near the same at 25 yards

[metricmonkeywrench]

Another brief update to close this out (I think) I still had plenty enough of the same bullets and powder for another box but this time with some standard LPP brass primed with Rem 2-1/2 primers to see what the baseline load with my gear looked like. Just like last time the same process and pistol was used.

Chronograph results
Min fps 793
Max fps 820
ES 27
Average fps 805
SD 8

So all in all I guess my answer is yes, I can use them safely so long as I stay within the normal loads using Bullseye.

[Larry Gibson]

"So all in all I guess my answer is yes, I can use them safely so long as I stay within the normal loads using Bullseye."

I would agree that is a safe assumption.

[JonB_in_Glencoe]

Federal and Remington also owned by ATK

Regarding Speer, CCI, Federal, and Remington.
They are now all owned by CSG.

published 10/17/2023:
The U.S.-based supergroup Vista Outdoor (https://vistaoutdoor dot com/), parent company of as many as 41 major brands including some historic ammunition and component brands such as Alliant powder, CCI, Estate cartridge, Federal, HEVI shot, Remington, and Speer, yesterday announced a definitive agreement to sell its sporting products business to Czechoslovak Group-CSG (https://czechoslovakgroup dot cz/it) for a corporate value of $1.91 billion (about 1.80 billion euros) in an all-cash transaction.

https://www.all4shooters.com/en/shoo...-to-csg-group/