To magnam or not to magnam primer?

[Mauser69]

4227=Ugh

Personally, I hate IMR 4227 - it is not only expensive, but also has never performed better than just mediocre for me. But my old load logs show where I was testing it with .357 magnum, and did some identical loads with both CCI 500 and CCI 550 primers - in those tests, that crappy powder actually had better accuracy with the standard primers.

Others have already stated this, but I will repeat - only a few powders seem to really benefit from magnum primers (and they are well known). It seems to me that at least 50% of all load manuals just indicate magnum primers for any load in a magnum cartridge because it is easier for them to print it that way.

Only a few of my old manuals specify a specific primer for each load, but I can't really remember which ones - I actually no longer pay much attention to the primer called for. Right now I have about 12,000 Winchester LP primers on the shelf (specified as both magnum and standard), and almost as many CCI 500 standard SP primers. I have only a thousand or so CCI 550 SP primers for the few H110 loads I do with .357 Mag. I use those three primers for ALL my handgun loads, no matter what may be specified in the load data.

 

[Carriertxv]

I came across a very good deal on Federal matched small pistol magnum primers awhile ago and bought 10,000. Non magnum small pistol primers were hard to get at the time. I have used them in all of my 357 loads and most of the 38 loads. I have found no difference but then again I don't have a chronograph to test.
If however I was loading at the very top of a load that called for non magnum primer then that is what I would use but anything below I have used the magnum primers with no drama.
Non magnum primers seem to be available again and at a decent price so I have switched back to using them in loads that call for them.

 

[Real Gun]

Personally, I hate IMR 4227 - it is not only expensive, but also has never performed better than just mediocre for me. But my old load logs show where I was testing it with .357 magnum, and did some identical loads with both CCI 500 and CCI 550 primers - in those tests, that crappy powder actually had better accuracy with the standard primers.

We're developing a side bar here, but I wonder if my result assessments are more positive because of my larger calibers (and primers) than your .357.

 

[Real Gun]

It seems to me that at least 50% of all load manuals just indicate magnum primers for any load in a magnum cartridge because it is easier for them to print it that way

.

Some of mine use an asterisk if needing to indicate a powder level exception to the cartridge level spec.

 

[rclark]

I have found some benefit in using magnum primers to get a more complete burn with HS-6. I will watch for signs of IMR 4227 being a problem with standard primers.

I don't know about complete burn (accuracy is what matters)... but the chronograph told the tale (96 ES vs 62 ES). I will use Magnum primers with HS-6 too going forward, although for the short range planned for the load (woods self defence) it isn't going to matter much.... As for 4227, again the chronograph told the tale. Back to back tests with .45 Colt, with 20g of 4227 under 255g SWC, ES was 138 with CCI-300 and 69 with magnum primer. On the other hand with .44 Special, the ES was closer, 65 for standard and 50 for Magnum. Still better but not significantly. In .357, I tested from 10.2 to 14.0g (with a magnum primer) but never marked any of the loads as accurate so I don't use 4227 for .357. But that's why we test and use a chronograph I suppose . YMMV of course.

 

[Savage99]

Undersize Unplated Winchester primers Lot #

One 100 tray of WLR unplated primers that fit and measure undersize has a lot # of DNL 836G on it's back.

 

[Real Gun]

I don't know about complete burn (accuracy is what matters)... but the chronograph told the tale (96 ES vs 62 ES). I will use Magnum primers with HS-6 too going forward, although for the short range planned for the load (woods self defence) it isn't going to matter much.... As for 4227, again the chronograph told the tale. Back to back tests with .45 Colt, with 20g of 4227 under 255g SWC, ES was 138 with CCI-300 and 69 with magnum primer. On the other hand with .44 Special, the ES was closer, 65 for standard and 50 for Magnum. Still better but not significantly. In .357, I tested from 10.2 to 14.0g (with a magnum primer) but never marked any of the loads as accurate so I don't use 4227 for .357. But that's why we test and use a chronograph I suppose . YMMV of course.

An important note is that I found Hodgdon's own loads for IMR4227 are accompanied by use of Winchester Large Pistol primers, which pass for magnums. I never considered the powder for 357 (small primers) since Lyman's indicated best results with HS-6.

I don't know about complete burn (accuracy is what matters)...

Sorry, but unburned grains of powder all over is definitely a deal breaker.

 

[TimSr]

For the OPs original question powder determines whether magnum primer is a better choice. Alliant states that none of their pistol powders benefit from a magnum primer.

CCI small rifle primers. Five shots.

304.5
318.2
332.3
384.2
299.9

Winchester small pistol primers.

363.3
280.6
369.7
275.9
351.9

Federal Magnum small pistol primers.

142.0
167.4
239.6
173.6
170.6

Go figure

The take away, a primer is a primer is a primer....not!
Don't assume standard primers are less powerful than magnum primers.

Primers aren't rated for their propulsion or power capabilites, but rather for how hot they burn, and the duration, (along with cup thickness). This data certainly demonstrates more inconsistancy between them than most people would expect. I did find this data very interesting, and may have some bearing on why it is so difficult for me to get consistant velocities from my 25 acp rounds, where the primer drives the bullet as much or more than the tiny powder charge.

It would be neat to explore primer constancy, not only between types, but also brands even further and tehir effect on small charge loads liek 23 and 32 acp that some reload.

 

[rclark]

Sorry, but unburned grains of powder all over is definitely a deal breaker.

You must not shoot any Black Powder then . Each to their own though. Respect that.

t I found Hodgdon's own loads for IMR4227 are accompanied by use of Winchester Large Pistol primers, which pass for magnums

In a back to back test, WLP did come out closer to the CCI-350. Ie, the velocity was nearer the CCI-350 load, than the CCI-300 load. It's a between primer .

 

[Real Gun]

Sorry, but unburned grains of powder all over is definitely a deal breaker.

You must not shoot any Black Powder then . Each to their own though. Respect that.

This is tedious. You could have assumed I meant for myself. Can you quote anything that was explicitly disrespectful, or do I have to take responsibility for every inference by an unlimited number of people.

A smokeless powder load with significant amounts of unburned powder is simply a bad load, that's all. Adding magnum primers to HS-6 to help with that was not my idea.