Today I decided to test some 9mm ammo that was loaded with SRP's in lieu of SPP's. My science skills are minimal, but I did try to eliminate as many variables as possible.

I started with a batch of once-fired, matching headstamp brass (CCI Blazer). Next I weighed my projectiles (Berry's 115gr Hollow Base Round Nose) until I collected 50 that weighed almost exactly 115 grains. For primers, I used Winchester Small Pistol and Winchester Small Rifle. They were purchased in the same trip to Cabela's a few years ago and have been stored in the same cupboard ever since. I loaded 50 rounds (25 with a SPP and 25 with a SRP) on my single stage press, weighing each powder charge.

Because I know the mistakes I'm capable of, I didn't just simply put the rounds in separate containers; I marked them with Sharpies.


Here are my rounds, ready for testing:


I met up with a couple buddies at the range, one of whom has a Labradar chronograph. It uses doppler radar to measure speeds so it isn't sensitive to light whatsoever--which means we could use it at our indoor range. Here's my buddy, testing some ammo:


My first test gun was my Gen5 G19. The second gun was a 5" 1911 9mm. As for the outcome, out of the G19, the rounds loaded with SPP's averaged 1048 fps at the muzzle, and the rounds loaded with SRP's averaged 1065 fps. Out of the 1911 with its extra inch of barrel, the SPP rounds averaged 1131 fps and the SRP rounds averaged 1151 fps. I checked my load data, and the speed with SPP's was about what I was expecting. The speeds from the rounds loaded with SRP's were still within the zone of what one could expect. All of the rounds that were loaded with SRP's fired on the first try and were every bit as accurate as the regular rounds. Here's a shot of some of the primers:


While I don't think my test conditions or small data sample are solid enough to draw any specific conclusions, I am at least satisfied that I won't blow myself up when swapping a SRP for a SPP when using low book load data. Since I shoot primarily pistols, it helps to know I've got an extra 10,000 primers for handgun use, should I need them.

Nicely done.

Good info. Nice to know; not as much difference as I’d have thought.

Excellent info, Wade. Thanks for sharing.

Interesting in these times

I haven't loaded for any handgun in decades. Just recently considered getting some of the handgun cartridge dies out, as choices are so limited when you can find ammo.

Would a Large Rifle Primer work in a large pistol (.44 or .45) load?

Awesome job, good to know.

Excellent info, thanks for taking the time to share.

I hadn't thought about it (mainly because I'm not anticipating needing to find out), but it appears that you might be able to make it work. I found this SAAMI spec chart during my initial research when I was considering swapping small rifle in for small pistol:



As you can see, SRP's and SPP's are dimensionally the same, but a LRP is .008" taller than a LPP. Would that be enough to make a difference? Maybe it'd bind a revolver's cylinder from rotating, but how much would it affect the cycling of an automatic? Additionally, I suppose you'd need to find out what the differences are in the priming compound of each. But, given the nature of the shooting community, you know it has to have been tried before. There's just too many shooters with the "mad scientist" gene for it not to have already been done.

Thank you for taking the time and sharing the info!

Might be mistaken,but I thought the major difference was the cup thickness in the primer.Handguns typically have lighter primer strike. Although I have used SR primers in a .357, but was primarily shooting them in ammo I used in a Rossi Model 92 carbine. They did go bang in my Ruger Security Six and S&W 686 however.

Right now with the AR crowd buying up every SR primer on the shelves I use the SP primers I have.

Based on an article by John Barsness - GUNS magazine pg 26 May 2009. [JB, formerly of Handloader is one of the most qualified gunwriters when it comes to primers and reloading in general]
Information from the Speer #14, Hornady #7, Nosler#6, and Lyman #49 reloading manuals, Alliant and Accurate Arms data.

CUP THICKNESS

Handgun primers have thinner cups than rifle primers, making them easier to ignite with the typically weaker firing pin fall of handguns. Small Pistol primer cups are .017" thick, while Large Pistol primer cups are .020" thick. This is the reason using handgun primers in .22 Hornet rifle loads sometimes results in pierced primers in some guns. Obviously their substitution in the high pressure .223 Remington would not be a good idea.

👍🏻👍🏻👍🏻

Thanks, Waders! I will try to do the same thing this week with some SRPs that I wouldn't mind allocating to pistol ammo. I'll be using mixed brass and 124 grain Precision Delta JRN that I don't intend to weigh for consistency. Report to follow.

Excellent empirical test, thanks for posting that. I would have figured the small rifle primers to be a good deal hotter than small pistol but your results show right around a 20 fps gain for both pistols which is less than 2% of the greater velocity (1.6% and 1.7% respectively) . One might see 20 fps difference in small pistol primers of two different brands or between standards and magnums


More data never hurts but your results across two firearms definitely show a trend. I doubt the same test repeated 10 more times or using different guns would vary significantly from what you're showing.

Now you've inspired me. I have just under 4,000 CCI 400's which I found out aren't supposed to be used in higher pressure rifle loads, and in fact one load in a .223 produced a pierced primer. Might have to do a little experimentation with a couple of .357's and .38's and get velocity readings with CCI-400 SRP vs. CCI-500 SPP. It'd be a good winter project.

Thank you kindly for the effort and information you have compiled!

Very relevant in today's political climate as I'm sure many folks have a stockpile of small rifle primers which will, in a pinch, substitute in small pistol loads.

I don't accept John claim that **all** Small Pistol cups are .017 and that ***all*** Large Pistol cups are .020 thick. This is likely true for some manufacturers, but there's a huge variance in the overall "toughness" of small pistol primers. Some of the European brands, especially S&B are very hard as they are designed for use in both pistols and SMG's. IME, failure's to fire or primers requiring double strikes are much more common with the hard European primers in regular handguns. In Contrast, Winchester primers, or at least the older Winchester's I'm still using on from my Y2K stash, are much softer and with all else being equal, primer ignition problems go away when they are employed.

Since I have a better stock of pistol primers right now, I'll be saving the S&B SP's in the event I need a substitute for SR's.

Sheeeit............now SRP's are gone gone gone

According to some internet reports, which I have no way to verify, but perhaps it would be a good question for John, in some instances, Magnum small pistol primers and normal small rifle primers have the exact same amount of priming compound.

Again, this are claims by unverified internet sources, and I'd feel more comfortable from someone whom I know had reputable industry connections, so take if for what it's worth.

Just about all primers are gone!

The only thing you might find are 50 BMG primers, the big musket caps, and occasionally shotgun primers.

So anyone experiment with stuffing a 50 BMG or Shotgun primer in a .223 case?

Interesting.

Curious to know what results of 124+P and 147gr cartridge loadings.

...probably wouldn't even need powder with the BMG primer!

Trudat.

As promised, I went out and ran my own test today to add to the knowledge base. The test guns were a Sig P365 and a Sig P365 XL. I used 124 grain Precision Delta jacketed round nose bullets, 4.3 grains of W231 and mixed brass, loaded to 1.155" OAL. All results were obtained using a Labradar.

The primers were recently purchased Federal No. 100 Small Pistol Primers and some older Federal No. 200 Small Rifle Primers in the old red box. (If I use any rifle primers in my pistols, these would be the ones, so I used those. Sorry.) The results were:

Sig P365
Federal Small Pistol- Average 1017, high 1028, low 1005, extreme spread (ES) 23, SD 7.6. 10 shots
Federal Small Rifle-Average 1020, high 1035, low 1002, ES 33, SD 9.7. 10 shots

Sig P365 XL
Federal Small Pistol-Average 1059, high 1076, low 1042, ES 34, SD 11.0. 10 shots
Federal Small Rifle- Average 1057, high 1084, low 1044, ES 39, SD 12.2. 10 shots
(Also, from notes, using Winchester Small Pistol Primers for Standard Loads-Average 1043, high 1060, low1025, ES 35, SD 13.9. 5 shots.)

There were no malfunctions. I did not test for accuracy, but the velocities are the same and I would not anticipate any difference. I should have compared the primers in the fired cases like Waders did, but I forgot. I will have to do that next time I load using SRPs.

Take care!

Cheyenne,

That's good stuff--no real difference between the two!

OK, I have been Googling around the Internet for opinions on doing the swap. Some have suggested that there can be breach face erosion if you use rifle primers on lower end loads because there will not be a good seal between the primer and the primer pocket. One guy claiming to be some kind of master reloading instructor guru suggests that equal velocities do not mean equal internal pressures, and that some primer/powder combos can cause an early high pressure spike that would still result in the same velocity as some primer/powder combos that do not spike as high. So, it may or may not be enough to just chronograph the same loads/guns with the only variable being a primer swap. Everyone should take a look for themselves and figure out who they want to believe and how much of a risk they are willing to take.

Sorry to be a pain, but I edited the post directly above this post two times. If you previously saw the post before the final edit, and you only look at new posts when you log in, please take a look at the above post. I know we have some technical experts here, and any comments or insight would be most appreciated. Thanks.

I've shot thousands of 9mm with SR primers and no leaks. Mostly CCI400 and older WSRP. I had a bunch left over after I stopped shooting HPR. My Tupperware guns and 1911's set them off just fine. I do not use reduced loads for 9mm, that may contribute to my success?

Statistically, no difference. Very good to know.

Thank you for taking the time to perform the tests and provide your detailed field report.

But is it claimed potentially possible pressure abnormality likely in this situation?

I doubt it.

The person had no data to support his claim on this particular point. He was talking theory and took the position that it was best to not take a chance. That was on SigTalk.

I was hoping that you would weigh in on this point.

Excellent follow up Cheyenne. Thanks for posting.

John Linbaugh told me years ago that in testing load data in pressure barrels for the 475L that rifle primers could increase pressure as much as 10,000 PSI without a corresponding increase in velocity

10K PSI and no change in velocity?

Not sure I buy that. I'd like to see the data and which variable correlate with the difference.
Were these alleged difference with using Magnum Rifle Primer?

No "corresponding" increase, I didn't say none and I didn't how much increase. I posted just like I was told. He said "rifle primers" and I didn't ask about magnum VS standard

jwp475, based on your experience, do you have an opinion as to whether the substitution of a small rifle primer (non-magnum) for a small pistol primer in a standard pressure 9mm would make a significant difference in pressure? I would appreciate any insight that you could provide.

Thanks!

I have no experience with this and only related what I was told by a man that had pressure tested them in the big revolver cartridges

Ok, thanks for responding.

The physics can not lie. If there is no change in velocity then there is no change in pressure. The pressure curve may change, but when only one variable is changed and results are the same, that implies the rest of the experiment remains the same.

That is not exactly true, as John Linebaugh's pressure tests proved in the Linbaugh revolver cartridges pressure increased with large rifle primers without a corresponding increase in velocity
The theory was that the rifle primer was over lighting to powder effectively increasing the burn rate
How this relates to 9mm and small rifle primers i have no idea

I've never tried that, but 40+ years ago I had a Ruger 77 in .308 Win that would not reliably fire my reloads with Large Rifle Primers. The firing pin would not dent the primer enough to ignite the primer. So I substituted Large Pistol Primers and problem solved.

Managed to get out today and add some data to the thread using a S&W M15 .38 Spl and a Ruger GP100 .357. Only tested three loads side by side with SP and SR primers but these are my go to loads for these guns so figured if this works I can use up a stash of CCI-400's that I don't want to use in my .223.

All results are 5 shots at 10' instrumental using an Oehler 35. Air temp was 35 deg.

S&W Model 15-6, 6" barrel
Winchester brass, my cast 158 grain WFN powder coated bullet (Accurate mold 358160) 5.5 gr. of True Blue
............CCI-500..........CCI-400
High............904................920
Low.............889................898
ES................15..................22
Avg..............896................909


Ruger GP-100 6" barrel
R-P brass, same 158 WFN cast and powder coated, 7.0 gr. True Blue
............CCI-500..........CCI-400
High..........1091..............1096
Low...........1049..............1030
ES...............42..................66
Avg...........1068..............1078

R-P brass, LBT 160 WFNGC, 16.0 gr. 296
............CCI-550..........CCI-400 - Note the small pistol magnum primer here, that's what would normally be used with 296 powder
High..........1318..............1348
Low...........1265..............1216
ES...............53.................132 (yowza!)
Avg...........1301..............1284

Groups for each load were not significantly different between the primers in all three examples and are about what might be expected firing two groups of the same load side by side. In fact this last load with 16.0 296 and a huge ES produced the tightest group of the day and the .38 load with CCI-400's was the next tightest. I have no way to measure pressure but brass extracted normally and obviously velocities stayed pretty close.

Basically this shows the same as Waders and Cheyenne - there really isn't any significant difference between using Small Pistol and Small Rifle primers although it does appear that the SR do provide a slight increase in velocity.


A final comment on the last load using 16.0 296 and CCI-400. The individual velocities in the string are 1216, 1292, 1288, 1348 and 1280. It looks like it wants to cluster around 1280-1290 fps with one very low and one very high reading, that skewed the ES badly and lowered the average so it was less than with the Small Pistol magnum primers. Or maybe that difference is true due to the SPM being hotter than standard SR primers. Don't have any ideas on that, as noted it produced the tightest group of the day at 25 yards. I might have to repeat that comparison with a couple of 10 shot strings.

Great information! Thank you, Jim!

Thanks to all who shared info
Well worth reading
Hank

Thanks for the research.

Y'all can tag this thread for when primers actually become available again...

I tried cci 400 in my 9mm load a week ago. Didn’t bring the chronograph. Shot them out my Glock they all shot fine. My load 4.1gr of bullseye, 124gr hi tek coated bullet.

Great information! Thanks!

Thanks! Good info.

tag

A good while back, when primers were actually very cheap, I picked up some Remington 650 SRPs just because I wasn't paying attention. They worked out fine in my .222, but I learned that they were intended for lower pressure cartridges like the .22 Hornet, and had thinner cups that could potentially blow out with the higher pressure of a modern cartridge.

When i learned about this I was well into one brick of them, and had an unopened brick that I gave to a guy that loaded for the Hornet. I still notice that partial brick of 650s from time to time, and occasionally have thought about acquiring a hornet to use them. Thinking now they'd be my substitute of choice for .38/.357 primers...

And there's still the little matter of the Hornet... Liking the 77/22 for that....

Here is a recent video put out by Super Vel Ammunition where they pressure tested and chronographed CCI small pistol, small pistol magnum and small pistol rifle primers in 9mm. The conclusion was that there is no difference. They also indicated that they function fine in most stock production guns.

Thanks for posting that, Cheyenne. That's good stuff--especially the pressure data.

My old packages of Federal 200 primers say small rifle or small magnum pistol on the box.

Thanks for the video!

Mine as well. Probably like the Remington 6-1/2 rifle primers .. appropriate for .22 Hornet, .25-20, and .32-20, but not for high pressure cases based on the .222 Remington.

I have messed around with interchanging small rifle and small pistol primers but not in a 9mm. I had a Single Seven .327 which runs at very very high pressure for a handgun. .327 pretty nearly matches .30 Carbine for pressure and the muzzle blast is abusive even if the recoil isn't. I chose to throttle mine back a bit. When I switched to loads with pressures akin to the .357 instead of .454, I also switched from small rifle primers to the Federal 200 primer. It seemed to help accuracy somewhat. (Gotta give Brian Pearce credit for the idea.)

Tom

Just an update:

I have fired about 2000 of my 9mm rounds that use a small rifle primer (both CCI and Winchester), and yesterday morning I had my first fail to fire. It did fire on the second try.

Other than that, the rounds have performed just like "normal" rounds. I haven't noticed any issues with pressure, and they are just as accurate as ammo loaded to the same specs, with the primer swap being the only difference.

I shot a group with my Sig P365XL with a Holosun red dot, and it turned out well for me. One round kept me in touch with reality, though. My shooting buddy laughed and said he better sign my target, because otherwise none of our friends would believe it. So he attested to the legitimacy of my claim.

EXCELLENT! 🎈🎊🎉🧨💯

Very nice thread! Thank you all!