SPM w/ 38 sp

[bsparker]

I've read a lot of mixed reviews about magnum primers, but I have the chance to buy some CCI 550s and the price is right. I'm looking to reload for .357 and .38. The powders I have available are 2400 and Trail Boss. I've seen mixed reports on magnumr primers with 2400 and have read a couple of threads about it on THR.

My question, what can I expect with magnum primers in .38 special using Trail Boss and 158 SWC? I've seen people suggesting to download them some and work your way up (standard instruction). None of the data I have state magnum for .38, but it's not always best to make an argument from silence.

Does any info on magnum primers for .38 with trail boss?

 

[1KPerDay]

I have no data to back me up but IMO you should be perfectly fine.

 

[Hartkopf]

I can't answer your question specifically but I have used Small Rifle Magnum primers in light 357 Magnum loads with zero issues. And Large Pistol Magnum primers in light 44 Special loads. And Small Rifle primers in hot 9mm loads. (shot near 1000 of these) And Small Rifle primers in medium 40S&W loads.

I work up like normal using published data but with different primers.

 

[GeoDudeFlorida]

Well, if you figure switching from Remington No.1-1/2 primers to CCI 500 primers requires a starting load and workup, then changing from CCI 500 to CCI 550 should also require a starting load and workup. Is it dangerous to change primers? Not really. Not any more dangerous than handloading in general. The potential problems of using a magnum primer instead of a standard primer are: excessive ignition depth and temperature causing detonation instead of deflagration, and failure to ignite the powder evenly causing fluctuations in burn rate and temperature. Either one is bad but the first is horrible. And about as likely as a snowstorm in Miami in June.

 

[dannyd]

I've read a lot of mixed reviews about magnum primers, but I have the chance to buy some CCI 550s and the price is right. I'm looking to reload for .357 and .38. The powders I have available are 2400 and Trail Boss. I've seen mixed reports on magnumr primers with 2400 and have read a couple of threads about it on THR.

My question, what can I expect with magnum primers in .38 special using Trail Boss and 158 SWC? I've seen people suggesting to download them some and work your way up (standard instruction). None of the data I have state magnum for .38, but it's not always best to make an argument from silence.

Does any info on magnum primers for .38 with trail boss?

Yes, I do and will help the consistency of velocity with the powder because of the volume of powder.

With 2400 magnum primers are recommended before of the volume of powder.

In a 357 magnum you would use 7.9 grains of unique to reach 1260 fps but you need 14.4 of 2400 to reach 1260 fps with the same 158 swc, so you are told in the manual to use a magnum primer for the 2400 but not the unique.

 

[AJC1]

The reason people focus so much on primers is accuracy. The idea of not unseating the bullet prior to powder burn is a big focus in rifle and why you see small primer 308, along with longer case life. A 38 has a large case volume compared to 9mm and that has been tested and discussed to death. Back off of max to test otherwise carry on....

 

[bsparker]

Thanks everyone. After further reading and the comments here, I'm meeting up to buy them. Price was good enough to not pass up and it's local, so no shipping/hazard. I'll proceed and see what results. Thanks

 

[dannyd]

Thanks everyone. After further reading and the comments here, I'm meeting up to buy them. Price was good enough to not pass up and it's local, so no shipping/hazard. I'll proceed and see what results. Thanks

It will work out. I lived in Northern Virginia 46 years ago.

 

[243winxb]

I've seen mixed reports on magnumr primers with 2400

357 mag Primer pressure test. https://castboolits.gunloads.com/sh...00-in-the-357-Magnum-with-6-different-primers

I use mags for 38, 357. WSPM currently, with Bullseye, Unique, 2400.

 

[AJC1]

357 mag Primer pressure test. https://castboolits.gunloads.com/sh...00-in-the-357-Magnum-with-6-different-primers

I use mags for 38, 357. WSPM currently, with Bullseye, Unique, 2400.

The eye opener in that article had nothing to do with primers and everything to do with the pressures from old h2400 to a2400. Backing down old load data seems prudent. People always complain about new data being lawyered up, that's why I want data with pressure. Great post.

 

[243winxb]

that article had nothing to do with primers

Look at pressures for 1 lot of powder. compare std to mag Primer.

Based on the large increase in psi over standard primers in this test it would appear the use of the Federal magnum SP primer would probably increase the psi significantly. If you really want to use those magnum primers then I suggest you drop the charge of any of those powders by 2 gr and work back up the same velocity as produced with a standard primer.

From link.

 

[GeoDudeFlorida]

Look at pressures for 1 lot of powder. compare std to mag Primer.

From link.

That second quote was in reference to Bullseye, Red Dot and Unique, not 2400.
Let’s bear in mind also the Hercules 2400 was closing on being 30 years old in 2019, the year the test was conducted. To paraphrase @Slamfire , people like to think smokeless powders are immortal; but they’re not. They start degrading the day they’re made.
Great article. Good data Conclusions: start low and work up. Always.

 

[243winxb]

Basic- Mag primers increase pressure? So it would seem.

Yes, old powder outgasses. Looses power & gets lighter in weight.

 

[Palladan44]

I've googled this question in my pre THR days, and came up with at least 5 forums asking this question and there is similar consensus across the board. Funny thing about SPM primers is that the vast majority of Magnum small pistol loads (357 Mag, 327) don't even require a SPM primer, except maybe WW296/H-110 loads.

 

[AJC1]

I've googled this question in my pre THR days, and came up with at least 5 forums asking this question and there is similar consensus across the board. Funny thing about SPM primers is that the vast majority of Magnum small pistol loads (357 Mag, 327) don't even require a SPM primer, except maybe WW296/H-110 loads.

I've seen people even argue h110 doesn't need it, but the manufacturer warning is clear enough for me!!!!!