357 Mag small pistol or small pistol mag primers

[WR Moore]

Some time back there was an extensive thread on the differences between primers that went into great detail on the qualities of the cup. IIRC, there wasn't any significant difference in thickness either between or within brands. However, there wasn't any information on the ductility of the metal. That is, how easily it deforms, which could make a difference in both sensitivity and deformation under pressure.

 

[38SPL HV]

Between the excellent and informed experience of many here, coupled with published Lyman Reloading data, I continue to use CCI550 magnum primers in all my 357 Magnum loads, mid range to magnum…"start low, work up…" and use a chronograph to keep yourself honest!

I finally have the space (Nevada, 85%+ is public land!, BIG state) and freedom to use a chronograph, back when living in the Northeast, indoor and outdoor ranges precluded their use…

 

[TexasViking]

I have never used Small Pistol Magnum Primers in my 357 Magnum 158 grain .358" diameter L-SWC loads over 6.0 grains of Unique. Does anyone recommend the magnum primers for this load?

It's very rare for a flake powder to need a magnum primer. 2400 in magnum loads comes to mind so far as getting recommendations for a mag primer, but just about as many will say it's not needed. With spherical and ball powders, it's often a matter of the bullet and the amount of powder used to obtain a specific velocity goal.

 

[LostintheOzone]

Magnum primers for everything that isn't flake or disk. Unique is a disk shaped powder so no, it doesn't need a mag primer.



W-296 and H-110 is flattened ball so use a mag primer.

2400 is cylinder shaped so use a mag primer.

I'm loading up some 357 this week with 2400. I don't have any mag primers but I wish I did.

 

[Skeet 028]

I just got 2 more pounds of Unique. I also have 2400 that I can load 357 with... And a 1000 Fed SPM primers... I also have plenty 296

 

[TexasViking]

Magnum primers for everything that isn't flake or disk. Unique is a disk shaped powder so no, it doesn't need a mag primer.



W-296 and H-110 is flattened ball so use a mag primer.

2400 is cylinder shaped so use a mag primer.

I'm loading up some 357 this week with 2400. I don't have any mag primers but I wish I did.

I started handloading with flake powders and .41 Magnum in 1986. Years ago, the first reports of lot variations with Blue Dot surfaced. I started using spherical or ball powders closest in burn rate: No 7 & No 9 for example. I've rarely revisited flake powders. One reason being that sphericals with the lowest bulk densities, are still denser than flakes. And since powder measures work on the principle of gravity? Another reason being excessive flash. Blue Dot and Power Pistol, and testing loads at night are pretty impressive if flamethrowers are your thing.
I was also aware that some well known writers sometimes reported getting better results using standard primers for max charges of W296/H110. And for those who are not aware, Accurate 11FS is another variant of the original 296, but with a flash suppressant added. Works pretty effectively, though a bit slow burning for even a 4" combat magnum.
I have really grown to like Ramshot Enforcer/AA 4100 made by Clermont in Belgium. Those people really know how to make great powders. In the case of .357 Mag, I've found that loads could be improved by using a standard vs magnum primer. It is slightly faster burning than W296, but misrepresented on several burn rate charts as being closer to AA No 9 than it is. That is not the case as can be determined by chargeweights in handload data.

 

[TexasViking]

I just got 2 more pounds of Unique. I also have 2400 that I can load 357 with... And a 1000 Fed SPM primers... I also have plenty 296

I should also mention that all standard primers are not created equal. WSPs tend to be a little warmer than CCI500s. My experiences with Federal SPMs has not been good. Maybe age or some other factor. WSPMs should light up W296 very easily. If you have standard primers, you might want to try both for 2400. I recently got a hold of some Ginex that I'll be testing soon. Appear to be clones of CCIs and made in Bosnia-Herzegovina. We'll see.

 

[ShootMeStraight]

I use small rifle magnum primers with N110 in 357. Works great!

 

[243winxb]

Read linked page to the bottom. https://www.ssusa.org/content/remington-1-pistol-primers/

CCI 400 Rifle primes are about the same. As pressure goes up, primers flow. Just like Rem 1 1/2. Or 6 1/2.

GOOGLE- "Mysteries And Misconceptions Of The All-Important Primer"