Small Pistol Magnum Primer substitute

[tomcat13]

With the current Primer Shortage, I find myself running Low on Small Pistol Magnum Primers & can't seem to locate them anywhere.
Has anyone ever Substituted Small Rifle Primers for SP Magnum Primers?
Just wondering if this is a Viable option.
Specifically for Loading 357 Mags.
Thx for any/all input!

 

[Mgderf]

I'm sure someone has done it.
Whether it was a good idea... that's another question altogether.

 

[Bill2905]

With the current Primer Shortage, I find myself running Low on Small Pistol Magnum Primers & can't seem to locate them anywhere.
Has anyone ever Substituted Small Rifle Primers for SP Magnum Primers?
Just wondering if this is a Viable option.
Specifically for Loading 357 Mags.
Thx for any/all input!

Are there any specific loads you are looking at doing this with?

 

[Slapstick]

This might help you answer your question. A good vid comparin SPP, SPMP and SRP in 9mm, I know it's not .357 but it is enlighting. I know people that using SRP for all their pistol loads right now without a problem so...? As always use your best judgement.

 

[Leo]

I have used small rifle in place of small pistol magnum primer. The one consideration is if the pistol has had a trigger job that makes the hammer hit softer. Many target trigger jobs on revolvers will not reliably set off a harder cup primer. Like any experiment, don't start at 100% maximum charge and test it over a chronograph before that becomes your steady diet.

 

[Robert Richardson]

What powder are you using?

 

[tomcat13]

What powder are you using?

Usually 2400
That being said, I was able to find a lb of IMR 4227 recently & hope to use it in future 357 Mag Loads.

 

[turnerdye1]

Subbing small rifle primers for small pistol - any hard data?

Has anyone done methodical comparison of small rifle and small pistol primers, with controlled loads and chrony data (and perhaps pressure testing)? Searched the Tube of Yous but nothing jumped out, and no general posts on the interwebz that methodically break this down. Or? Magnum primers...

www.indianagunowners.com

I did a very simple comparison back in 2020 swapping small pistol and small rifle primers. Not sure if it'll help you but the results are half way down the front page. I still have a stock of SPP but wouldn't hesitate swapping to SRP if I ran out.

 

[Robert Richardson]

I believe in this case, is the standard SR primer hot enough to be reliable to ignite the magnum type powder.

 

[BugI02]

I have not used SRPs with 357 magnum loads yet, although I likely will do so soon. I have used some for 9mm and 38 super and they all went bang

What I have read seems to indicate that the difference between SPP and SRP is the rifle primer already does burn hotter and also makes a greater volume of gas from the ignition of the primer material. Personally, I would conclude that their use would be undesirable in compressed or near compressed loads in pistol cartridges and I would hesitate to use them in something where bullet retention by the case was already an issue like 357 sig. It is my understanding that it is quite common for competitive pistol shooters to make this substitution in their handloads

 

[VERT]

I wouldn’t hesitate to use Small Rifle Primers.

If there is concern and I see the OP is close to Louisville. I have some SPM primers laying around that I could swap.

 

[tomcat13]

I wouldn’t hesitate to use Small Rifle Primers.

If there is concern and I see the OP is close to Louisville. I have some SPM primers laying around that I could swap.

Thanks for the response & Offer. I'm gonna give the SRP's a few test runs & If the results are unsatisfactory/unreliable, I may take you up on some Swapping.

 

[indydave]

i have used large rifle primers in 44 mag hunting loads fired in a rifle (h&R handi-rifle and a ruger 77/44 ) zero change in poi ot velocity

 

[Creedmoor]

With the current Primer Shortage, I find myself running Low on Small Pistol Magnum Primers & can't seem to locate them anywhere.
Has anyone ever Substituted Small Rifle Primers for SP Magnum Primers?
Just wondering if this is a Viable option.
Specifically for Loading 357 Mags.
Thx for any/all input!

What loading manual is telling you that you need small mag primers with 2400 in 357 mag?

 

[tomcat13]

What loading manual is telling you that you need small mag primers with 2400 in 357 mag?

View attachment 193983

Lyman Manual

 

[Creedmoor]

Lyman Manual

Well, i've loaded 357 and 44 mag for better than 40 years, normally as compressed loads. Never used mag primers for either.
The above screenshot is from the manufacturer, cci 500's are a standard primer.

I have a 20-30 yr old Lyman, I will take a look at it this afternoon.

 

[tomcat13]

Well, i've loaded 357 and 44 mag for better than 40 years, normally as compressed loads. Never used mag primers for either.
The above screenshot is from the manufacturer, cci 500's are a standard primer.

I have a 20-30 yr old Lyman, I will take a look at it this afternoon.

Great to hear about your success loading 357's & 44's with Standard Primers (I also load 44 Mags) & I'll certainly try some Test lds-using Standard Primers.
Here are pics from my Lyman Manual (49th Edition):




Thanks for the Input!

 

[Hawkeye7br]

I started loading for the 357 Maximum with 296 and 4227 in the early 80's. CCI 400 was the standard primer per many sources. I also used 357 mag cases when I wanted milder loads, and it was logical to continue with SRP in magnum cases. I ran 180 grain bullets for handgun silo at something under maximum pressure.

 

[BugI02]

i have used large rifle primers in 44 mag hunting loads fired in a rifle (h&R handi-rifle and a ruger 77/44 ) zero change in poi ot velocity

Dave, I would urge caution doing this

The SAAMI dimension range of a large pistol primer depth is 0.115 to 0.126

The SAAMI dimension range of a large rifle primer depth is 0.123 to 0.136

unlike the dimensions for SPP and SRP, which are functionally identical, as is the spec depth of the primer pocket, the spec MAX depth of the large pistol primer pocket is 0.123, which is the MINIMUM depth of the LRP. The use of a LRP in a large pistol application leads to a high likelihood that the primer will not be seated flush with or below the cartridge base but will be proud

You should likely be fine with the single shot or the bolt gun, but I would hesitate to use such rounds in either a tube fed gun, like a lever action, or a revolver

 

[VinceU1]

I have used small rifle in place of small pistol magnum primer. The one consideration is if the pistol has had a trigger job that makes the hammer hit softer. Many target trigger jobs on revolvers will not reliably set off a harder cup primer. Like any experiment, don't start at 100% maximum charge and test it over a chronograph before that becomes your steady diet.

What he said.
I've used small rifle primers in ALL my pistols using powders from W231 through HS6 and W296 and they've ignited every single load without fail. Been doing this since 2000 or so when 38Super loads where loaded to Oh My God scary levels and a regular normal pistol primer would fail due to pressure levels.