Given the dismal availability of primers these days, all I have for loading up .357 Magnum are WSP (not WSPM).

Question: Is that non-Magnum primer hot enough to optimally ignite this powder charge?

.357 Magnum
185 gr. hard cast lead (Beartooth( (GC)
13.8 gr. Ramshot Enforcer
Primer = WSP (non-Magnum)
COAL = 1.590”
Trim length = 1.290”
MV = _________ fps (est. 1,220 fps)
ME = _________ ft. lbs. (est. 612 ft. lbs.)
NOTE: This load in Lee’s 2d Edition manual, 35,000 psi load.

Might want to ask this in the Reloading forum under Armory.

It's a spherical powder you're using, which will probably have the greatest over impact on the primer performance. Spherical powders typically need magnum primers to burn completely.

You will probably see decreased performance and unburnt powder, but it will still go bang.

https://www.ramshot.com/faq/

There is unfortunately no simple solution or recommendation, because the primers of different manufacturers can differ quite substantially even when rated for the same category.

However, as far as safety is concerned for the most general and popular calibers standard primers of most manufacturers will work in both the handgun and rifle categories.


The belief that all spherical powders must be combined with magnum primers is not true. This might have been the case in the early years. However, what is suggested is that as soon as the capacity of a typical rifle caliber goes beyond 70 grains it will be good to use a higher energy "Magnum" rated primer. In the case of handguns its more difficult and as far as our Accurate products is concerned it will be good to use magnum primers when the Chargemass exceeds 20grains in a typical bigger bore caliber such as 44 and larger.


As far as accuracy is concerned, which depends on the intricate/complex interactions of the components and weapon system/platform a change in any one of the major components including primers can have a significant effect, for better or worse. Therefore it will be wise to experiment with different primers if a problematic situation arises.

The surest answer is likely going to come from calling Ramshot.


I would hope they have already had this inquiry and likely ballistic testing done.  

My off the cuff guess is you will be fine in warm weather but there might still be a risk in cold winter weather.  Really just the over generalized primer warning reiterated.  

87% of my revolver loads are weaksauce.


You could do your own testing with a chronograph and a chest freezer.  Freeze the ammo and the gun.  The barrel temp at least in rifles is just as much a factor as the ammo.  

Western/Ramshot online reloading data for 357 Magnum shows they used Winchester Small Pistol Magnum primers.  The 357 Magnum load with 13.8 grains of Enforcer with Lead CP bullet with a Flat Point Gas Check had a pressure of 34952 PSI.   Their 357 Maximum data shows they used CCI 450 magnum small rifle primers with a max pressure on one load of 40,000 PSI.

The main difference in standard primers to magnum primers is cup thickness and or hardness to resist pierced primers or slam fires with floating firing pins.  Some primers are hotter or different flame but I’m concerned about the cup thickness.   Super Vel had a video comparing the difference in pressure and velocities between standard pistol and magnum pistol primers.   They also compared CCI standard rifle primers to CCI standard and magnum primers.




https://www.youtube.com/watch?v=NGVRGsoOr6k

I personally would not

I did one time and I believe it played a partial role in bulging my cylinder.

I also used a fast powder (231) that only filled the case about 1/3rd.

I believe the combination lead to pressure spikes due to inconsistent burn depending on the position of the powder in the case at the time of ignition.

I will never load .357 again without a slower powder that nearly fills the case and mag primers

What are you firing it in?  I load rifle .357 separately from handgun 357.   The only use I have for small magnum primers is with heavy loads of 2400.

Just back off the load a bit and work up to what you are happy with using the different primers, see what sort of consistency you get.

Standard small pistol primers are designed for <20,000 psi. Magnum pistol primers double that pressure <40,000 psi.

You can use Remington 6.5 small rifle primers, they are designed for small caliber low pressure <40,000 psi rifle loads and really aren't strong enough for anything else. CCI-400's and Russian kvb-223 primers will work in magnum pistol loads too. It's almost always safe to use a primer designed for higher pressures in a lower pressure application. It's rarely advisable to do the opposite.

If all you have are standard small pistol primers I would use .357 Magnum starting loads and nothing heavier. Pay close attention to the primers. Switch to lighter charges of faster burning powders is you observe any problems.

WW-231 will work fine in .357 Magnum shooting light loads combined with standard pistol primers. You will get in trouble if you are trying to make the standard pistol primers withstand full power charges.

Youll be fine

35k psi is also what 9mm operates at. It uses a SPP not a magnum.

I have tried using SRP in place of SPMP but I have had issues with ignition with my revolver; cup is too hard

"Standard small pistol primers are designed for <20,000 psi"

Funny that does not jive with SAAMI Spec.
9×19mm Parabellum
Primer typeBerdan or Boxer small pistol
Maximum pressure (CIP)235.00 MPa (34,084 psi)
Maximum pressure (SAAMI)241.3165 MPa (35,000.00 psi)

https://www.ar15.com/forums/armory/Conversation_With_CCI_Tech_About_SPM_vs_SR_Primers/42-320004/?

Just an FYI.

I’ve seen this info in several forums, likely the same poster who claims CCI tech states CCI 400 & 550 are the same item re: cup thickness & primer mix amount.  So, if OP has any CCI400s?

I’ve used CCI400s for 5.7, .38 Spl & .357, light & magnum loads with no difference, but i start low & work my way up.  I also use CCI400 in my .223 plinking loads.

YMMV.