Pressure:Magnum vs standard primers

Sea Buck · May 5, 2009, 09:46 PM

How much extra pressure can I expect when using Mag primers for .357/.38 loads. I'm out of std primers,and out of Bluedot,my favorite, and have gone to Herco.Bullseye and Unique are a thing of the past.Better to look at shotgun powders it's all thats out there.I reload for 125 gr jhp,148 gr wc, 158gr jhp, 160gr swc. Herco is a little faster. Where I could go to the high numbers with Blue dot it's just not possible with Herco.I guess this is the game now...get inventive with reloading, with safety and research, or give up shooting:NEVER!

Sevens · May 5, 2009, 10:12 PM

So then... .38 or .357?

When you figure that SAAMI spec for .38 Special is 15,000 to 17,000 PSI (+p) and every .357 Mag revolver is rated for ammo built to 35,000 PSI, I would think you could go directly to a magnum primer for anything in .38 Special, if you are shooting them out of a .357 Mag revolver.

Some folks that have pondered and/or tested different primers have come up with an extra 5,000 PSI in a load where a magnum primer was inserted in place of a regular primer. But you can get pressure increases just from changing primer BRANDS or even lot to lot from the same primer.

If you aren't loading max and over max loads in the first place, you should be able to safely insert a magnum primer if that's all you happen to have.

May 5, 2009, 09:46 PM	#1
Sea Buck Senior Member Join Date: September 9, 2008 Location: New England,Florida Snow Bird Posts: 312	Pressure:Magnum vs standard primers How much extra pressure can I expect when using Mag primers for .357/.38 loads. I'm out of std primers,and out of Bluedot,my favorite, and have gone to Herco.Bullseye and Unique are a thing of the past.Better to look at shotgun powders it's all thats out there.I reload for 125 gr jhp,148 gr wc, 158gr jhp, 160gr swc. Herco is a little faster. Where I could go to the high numbers with Blue dot it's just not possible with Herco.I guess this is the game now...get inventive with reloading, with safety and research, or give up shooting:NEVER!

May 5, 2009, 10:12 PM	#2
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	So then... .38 or .357? When you figure that SAAMI spec for .38 Special is 15,000 to 17,000 PSI (+p) and every .357 Mag revolver is rated for ammo built to 35,000 PSI, I would think you could go directly to a magnum primer for anything in .38 Special, if you are shooting them out of a .357 Mag revolver. Some folks that have pondered and/or tested different primers have come up with an extra 5,000 PSI in a load where a magnum primer was inserted in place of a regular primer. But you can get pressure increases just from changing primer BRANDS or even lot to lot from the same primer. If you aren't loading max and over max loads in the first place, you should be able to safely insert a magnum primer if that's all you happen to have. __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.