Substitutes for Small Pistol Magnum Primers

[robertbank]

Today I loaded up the last of my SPM Primers. I have a source for some Small Rifle Primers. Would they be a reasonable substitute for the Magnum Small Pistol Primers.? Caliber is .357 Magnim.

Take Care

bob

[Winger Ed.]

Not in a handgun, but I've used them in my .357 Marlin, and a Class III Mac in .380.
I'm not sure if the RP is hotter than the SPM, but I don't use max powder charges anyway.

I don't think you'll have any issues with the hammer strike not being hard enough,
but a couple of (edit) mild loads will tell ya pretty quickly..

[Finster101]

I think rifle primers sit slightly taller. I would seat one or maybe even a couple of spent ones and make sure it did not sit too proud and tie up the gun.

[Winger Ed.]

I think rifle primers sit slightly taller. .

I never had problems with SP & SR, or I'm not smart enough to notice.
I've never mixed & matched large primers, but I've heard LR are noticeably taller than LP.

[M-Tecs]

Small rifle and small pistol are the same height.

Large rifle and pistol are not.

Remington 6 1/s's or CCI 400's have the thinnest cups. Hardness is also a factor as is the priming compound. The Federals tend to be the most sensitive but they changed the compound recently so I do not know if that is still true.

If they reliably ignite you will be ok. If you try just primed cased it will likely lock a revolver up since the primer doesn't reseat.

[robertbank]

I was more concerned about if there was any difference in performance between SPMP and SRP. They are the same size and both ignite larger quantities of powder compared to pistol cases such as 9mm and 38spl for example.

Take Care
Bob

[M-Tecs]

I was more concerned about if there was any difference in performance between SPMP and SRP. They are the same size and both ignite larger quantities of powder compared to pistol cases such as 9mm and 38spl for example.

Take Care
Bob

Maybe Larry will pipe in with some actual pressure date. I know lots of people using them with no issues other than light strikes due two the thicker/harder cup . The lower brisance would be my first choice. I do remember reading one of the primers used the same amount of compound between rifle and pistol with the only difference being cup thickness. That was per the manufacture but I don't remember which it was.

https://castboolits.gunloads.com/showthread.php?374804-Is-there-such-a-thing-as-a-primer-brisance-chart-for-small-rifle-primers

https://web.archive.org/web/20150304181523/http://riflemansjournal.blogspot.com:80/2009/06/primers-small-rifle-primer-study.html

[Finster101]

I never had problems with SP & SR, or I'm not smart enough to notice.
I've never mixed & matched large primers, but I've heard LR are noticeably taller than LP.


Thanks to you and M-tecs for clearing that up. I have never tried them, just seemed to remember reading something about it.

[Loudenboomer]

I've been told CCI small pistol magnum and CCI small rifle are the same primer. I've used these 2 interchangeably without issue.

[Larry Gibson]

I ran a test in the 357 with different primers and 2400 powder. Data is in first post. Further testing of various powders with different primers in the 357 and other cartridges indicate that different powders burn differently when different primers are used. Appears the deterrent coating on the powder to control the burn rate is the big variable.

Note the large increase in psi when the WSPM was used vs the WSP prime, especially with the Alliant 2400r.


https://castboolits.gunloads.com/showthread.php?381165-Test-of-Hercules-vs-Alliant-2400-in-the-357-Magnum-with-6-different-primers

[358429]

Today I loaded up the last of my SPM Primers. I have a source for some Small Rifle Primers. Would they be a reasonable substitute for the Magnum Small Pistol Primers.? Caliber is .357 Magnim.

Take Care

bobMake a box of ammunition and a clean gun(s) and test to confirm function. (Ignition test)

I have used small rifle, small pistol & magnum, in 9x19, 38 special and 357 magnum, all interchangably with out problems with mid range data. (Plinking loads)

My repeatable good results may or may not carry over for others due to unknown variations in the guns, loading equiptment, environment or test process. Your mileage may vary.

Be safe.




Sent from my SM-G930T using Tapatalk

[robertbank]

Make a box of ammunition and a clean gun(s) and test to confirm function. (Ignition test)

I have used small rifle, small pistol & magnum, in 9x19, 38 special and 357 magnum, all interchangably with out problems with mid range data. (Plinking loads)

My repeatable good results may or may not carry over for others due to unknown variations in the guns, loading equiptment, environment or test process. Your mileage may vary.

Be safe.




Sent from my SM-G930T using Tapatalk

Will be at my bench shortly to do as you suggest. I may back down on my 358429 load a bit. I do like and use Ron Flexalls load of 14.5 gr of 4227 under the bullet. The load in my Marlin 1894 and GP-100 is very accurate and packs a desired thump I am looking for in Wilderness Carry. I have used SRP in my GP-100 and 686 No-Dash previously so I am not worried about ignition problems due to primer thickness.

I have some lighter load data using SPMP so I will load up some of the same loads using SRP and see if there is a noticeable difference. From all your replies I feel more comfortable now in doing so. I am not one to go out and try inventing an improved wheel if others with experience in my problem have gone before. Much obliged guys. I will get back here with my results. Looks like the coming week may actually involve sunshine and blue skies for at least a couple of days.

This summer aside there is a certain attraction living in some parts of Southern BC in our desert country. Was not so pleasant this summer but there you are.

All the best.

Take Care

Bob

[dannyd]

I use WSR primers in my 38 special loads with Bullseye, HP38, 700x. Got the best numbers on the Chronograph with the WSR primers under 15 FPS standard deviation.

[robertbank]

I use WSR primers in my 38 special loads with Bullseye, HP38, 700x. Got the best numbers on the Chronograph with the WSR primers under 15 FPS standard deviation.

One load I use a lot in my 38spl is 3.4 gr of 700X under my RCBS 158GR RN bullet. Very accurate and clean burning my GP-100 and Model 10 5".

Take Care

Bob

[dla]

Unless you're using slow ball powders like H120/W296 I doubt you'll notice the difference. A powder like 2400 can be ignited with anything.

[dannyd]

[QUOTE=robertbank;5272875]One load I use a lot in my 38spl is 3.4 gr of 700X 7hder my RCBS 158GR RN bullet. Very accurate and clean burning my GP-100 and Model 10 5"/

Take Care





Use 158 SWC and 170 Full Wad cutter. Got 8 lbs. to load shotgun and thought I try it; works great in the GP100 and Ruger Bisley.

[downzero]

Unless you're using slow ball powders like H120/W296 I doubt you'll notice the difference. A powder like 2400 can be ignited with anything.

Unless he's using magnum powders that require magnum primers (like the two you suggested and a few others, NOT 2400), he shouldn't be using magnum primers anyway.

[robertbank]

I don't use Magnum powders in 38spl or 9MM if that is a concern. I use them in .357mag loads where they are called for in the loading manuals. The absence of magnum primers on my shelf has sent me looking for alternatives. The SRP appears to be a solution for some applications; SPP for other applications with the .357mag.

Take Care

Bob

[zarrinvz24]

For small sized primers, I exclusively use Small Rifle. In everything from 9mm on up. I believe that Larry Gibson or Outpost did some experiments and found no pressure difference between the two. Regardless, I ensure to work up my loads from starting loads using the SRP. Haven't had any issues yet and I've been doing it for years. I'm not sure if you will find this helpful or not, but the Military 9mm is loaded with SRP as well - the same ones as the M855 5.56 ammunition.

[dannyd]

I have been testing Large Rifle and Pistol Primers in 38 Special and 357 Magnum for use in my Tc’s and Encore rifles. Mill out the primer pockets and use the same powder charge and bullet, so far best numbers on the chronograph as far as standard deviation.

Wanted a backup in case I ran out of Small pistol and rifle.

[robertbank]

I am about to score 5,000 SPP for $4.50CDN/100. They are made in Bosnia. The last batch we bought were a PITA to prime. Anywhere from 25% to 50% would not seat fully using my Dillon 550B. I ended up seating them with my RCBS Rockchucker. More leverage with the single stage. At that price and given the shortage/pricing of primers my buddy and I decided while a pain to load the pricing was to good to pass on. They work ok in my revolvers and carbines.

This purchase will bring my SPP stash near 10K which should get me through most of next year. Hopefully the Republicans will be polling strong down your way and some of the panic buying will ease up along with the ending of the D version of Covid. There is a light in the end of the tunnel...hopefully it is not a train.

Update got them. with tax and shipping it will work out to about $5.70/100 Cdn. Purelator will have them at my door by Friday.
Take Care

Bob

[jimlj]

Given the choice I will only buy small rifle primers for anything needing a small primer. Back off your powder by a grain and work up to a load that is safe and accurate to your satisfaction.
Super Vel did a test with different primers. https://www.youtube.com/watch?v=NGVRGsoOr6k

[Tar Heel]

"Brisance" is a term often mistakenly used as a synonym for primer potency (or mistakenly identified by spellcheck programs as not being a real word). Not only is it a real word, brisance actually refers to the shattering effect of the sudden release of energy in an explosion. However, propellant powders are designed to burn with their powder granules intact, not shattered by the ignition of the primer. For igniting propellants, high brisance is an undesirable primer property. For this reason, very small quantities (a maximum of 45 milligrams) of priming compounds are normally used for ignition purposes.

Magnum primers develop hotter and longer flame duration. More "thrust" if you will and hotter thrust. While I love the word brisiance, I had to work it out of my vocabulary for primers. Whilst in the USMC of course, the Gunny would call for a charge with more brisiance and then we would get stuff that would cut through steel like a hot knife through butter! Awesome stuff.

I wonder if the debate between standard primers and magnum primers to ignite BPCR charges exists in the smokeless world. I have not seen too much discussion on the topic like I have in the BPCR theatre. Anybody have anything to share about that?