Standard vs magum primers. I'm going to find out for myself.

[mmb617]

I don’t see this test as being all that credible .
no one should conclude based on this test that there is no difference and you can just switch them out regardless of charge or headstamp .

I agree that no one should take my results as having any bearing on what they might find. Way too many variables for that. I'm basically just BS'ing with the guys on what I found, not saying they would see similar results.

Which is why I put this disclaimer in my very first post in the thread:

Of course that doesn't mean anybody else will agree with what I find, but this is just for my own information anyways.

Just about everybody here has far more experience with reloading than I do. I just thought it was an interesting topic for discussion because every gun forum I'm on has some members who feel there's little if any difference in the primers and others who feel there is a big difference. With that type of situation I like to experiment and draw my own conclusions, but that doesn't mean I'm calling anybody else wrong.

 

[JJFitch]

The purpose of magnum primers is to provide efficient ignition of some slower burning powders such as MAGNUM powders. To do this manufacturers produce a longer "spark" or brisance. This fact alone may not create higher pressures. The testing that I've done has yielded similar results as stated above.
Magnum primers may have a harder cup to facilitate higher pressures.
Federal standard primers are easier to ignite.
Never use pistol primers in rifles, period!
Some rifle primers will be "high" if used in standard pistol cases.

"Never deviate from published load data unless you are willing to assume the risk k of injury and resultant mechanical damage"!

Smiles,

 

[Obturation]

I work up all my loads with magnum primers, I have used standard primers when I can't find magnums for cartridges that don't call for magnum primers in the load data. As long as the load is worked up with the mag primer, going to a softer and possibly less powerful primer won't hurt anything. For big cases , magnum powders (h110& others), very low temperatures or high pressure I just stick with the magnum primers.
I've never been able to tell any difference

 

[Metal God]

I did an apples to apples standard vs magnum primer test in a full 5.56 load work up using 55g FMJ-BT , H-335 , LC-12 cases and CCI primers . This was working up from minimum to max charges in .5gr increments . I don't remember the exact charges but think it was 23.5gr through 26gr .

The results were interesting because the Magnum primers were much less consistent across the board . Much higher SD/HD resulting in wacky avg velocities compared to the standard CCI #400 primers . The one thing I believe may clean up those results is crimping the bullet . I did not crimp any of the test rounds and it's been theorized that the more powerful magnum primers were dislodging the bullet before the powder started fully burning . The thinking is a crimp would hold the bullet in place just a tad longer allowing for a more consistent burn . It's an interesting theory but I've never reran the test with crimped bullets .

 

[rskent]

I did an apples to apples standard vs magnum primer test

I understand your test. I just don’t understand your conclusion. Why wouldn’t you find the best load and go from there. Also, I understand that different velocities could (might) be a problem.
Then again, they might not be significant enough to matter on target. How tight does that load shoot anyway?

For a long time my short line (service rifle) load was a 52 smk over 335. After having a second failure to ignite during a match I switched to magnum primers.
No changes to the load were needed. No difference in average score. No more cleaning powder out of the chamber during a match.

 

[alfsauve]

......
Never use pistol primers in rifles, period!
......
"Never deviate from published load data unless you are willing to assume the risk k of injury and resultant mechanical damage"!,

So just when you thought it safe to get back in the water.


What do you do when the publish load data for a rifle cartridge says use Pistol primer?


Yes, obviously I wouldn't ask if there wasn't, there is at least one.
https://load-data.nosler.com/load-data/458-socom/

 

[grammontS]

So small pistol magnum primers are fine to use in 9mm loads? I'm new to reloading and primers aren't the easiest to find here in Taxachusetts ( and I refuse to pay the hazmat fee for shipping them). One local dealer does have a good amount of small pistol magnum primers , so I guess I'll go.scoop them up. I found this to be a good topic .

 

[Charlie98]

I did an apples to apples standard vs magnum primer test in a full 5.56 load work up using 55g FMJ-BT , H-335 , LC-12 cases and CCI primers . This was working up from minimum to max charges in .5gr increments . I don't remember the exact charges but think it was 23.5gr through 26gr .

The results were interesting because the Magnum primers were much less consistent across the board . Much higher SD/HD resulting in wacky avg velocities compared to the standard CCI #400 primers . The one thing I believe may clean up those results is crimping the bullet . I did not crimp any of the test rounds and it's been theorized that the more powerful magnum primers were dislodging the bullet before the powder started fully burning . The thinking is a crimp would hold the bullet in place just a tad longer allowing for a more consistent burn . It's an interesting theory but I've never reran the test with crimped bullets .

That mimics my experience as noted in post #7 above. Although I was not working up... I used a single, existing load to experiment with. My bullets were crimped, and very likely had the patented Charlie98 Death Grip Crimp I was famous for back in those days... so I would say crimp didn't make much difference between our individual test results. My loads were fired out of my 20" Colt H-bar.

I understand the data recommendations for Magnum primers with ball powders. The data providers are trying to make sure there is consistent ignition at all temperature ranges with 'hard to ignite' ball powders... like H110/W296 and H335, for example. I shoot in 100+ F heat in the NV desert... I don't think I'm going to have a problem firing off a case full of H335, but I could see where shooting in sub-freezing temps, particularly where the ammunition is that cold, too, might be an issue. I'm sure there are other instances.

 

[Charlie98]

So small pistol magnum primers are fine to use in 9mm loads? I'm new to reloading and primers aren't the easiest to find here in Taxachusetts ( and I refuse to pay the hazmat fee for shipping them). One local dealer does have a good amount of small pistol magnum primers , so I guess I'll go.scoop them up. I found this to be a good topic .

Yes, and NO.

The 9mm is a high-pressure cartridge where one small change in the cartridge work up can lead to pressure issues. Something as simple as bullet seating depth... or a Magnum primer... can raise pressure beyond safe limits. If you start from scratch and work the load up with the Magnum primer, watching for pressure signs along the way, you would likely be OK, but if you are planning on loading at the limits of data, I would use the correct components.

 

[grammontS]

Yes, and NO.

The 9mm is a high-pressure cartridge where one small change in the cartridge work up can lead to pressure issues. Something as simple as bullet seating depth... or a Magnum primer... can raise pressure beyond safe limits. If you start from scratch and work the load up with the Magnum primer, watching for pressure signs along the way, you would likely be OK, but if you are planning on loading at the limits of data, I would use the correct components.

I've been loading at the minimum powder charge , I see no reason to max out my loads for target shooting.

 

[Charlie98]

I've been loading at the minimum powder charge , I see no reason to max out my loads for target shooting.

Then you should be OK. Because you are a new reloader, I wanted to make the point that you do have to be careful when you start swapping components around... I'm not busting your chops. If you already worked up a load with a standard primer, for example, and you were at mid to max data, it would be wise to reduce and rework with the introduction of a Magnum primer as a substitute. I would say the same with a switch to a different bullet.

 

[grammontS]

All info is much appreciated

 

[Metal God]

I understand your test. I just don’t understand your conclusion. Why wouldn’t you find the best load and go from there. Also, I understand that different velocities could (might) be a problem.
Then again, they might not be significant enough to matter on target. How tight does that load shoot anyway?

I was not looking for the best load , had that worked out years before . The test was purely to see the difference between standard and magnum primers . I don't even remember what the groups were like and if the magnum primers best group was at a different charge . I do save all my notes and targets when doing things like this so sometime today I'll go fish through them and come back with specific numbers . Sometimes when doing test like this one I don't look for groups because I've already done that and will use a red dot at 50yds . Not sure If I did that here but might have .

 

[Walkalong]

What do you do when the publish load data for a rifle cartridge says use Pistol primer?


Yes, obviously I wouldn't ask if there wasn't, there is at least one.
https://load-data.nosler.com/load-data/458-socom/

.22 Hornet is another where some folks use pistol primers, but the pressure is low compared to most rifle calibers. What pressures does the Socom run at?

 

[Metal God]

The socom can run subsonic like the 300blk . I’m assuming it’s the subs that can run pistol primers . They both also have supersonic charges that are in the the 50k to 60k psi range . I wouldn’t use pistol primers for those .

 

[Walkalong]

They both also have supersonic charges that are in the the 50k to 60k psi range . I wouldn’t use pistol primers for those .

Ouch, me either.

 

[Metal God]

The socom can run subsonic like the 300blk . I’m assuming it’s the subs that can run pistol primers . They both also have supersonic charges that are in the the 50k to 60k psi range . I wouldn’t use pistol primers for those .

I need to correct my numbers , They only reach 40k psi so not to different then some magnum pistol cartridges . I guess magnum pistol primers would work for those loads .

 

[Toprudder]

I need to correct my numbers , They only reach 40k psi so not to different then some magnum pistol cartridges . I guess magnum pistol primers would work for those loads .

I think you were partially correct.

Max pressure for 300blk is similar to 223/5.56 at 55k. The 458 Socom is limited to 35k, I suspect due to the limitations of the locking lugs of the AR and the forces a larger diameter case would generate.

 

[GaryL]

So small pistol magnum primers are fine to use in 9mm loads? I'm new to reloading and primers aren't the easiest to find here in Taxachusetts ( and I refuse to pay the hazmat fee for shipping them). One local dealer does have a good amount of small pistol magnum primers , so I guess I'll go.scoop them up. I found this to be a good topic .

I would say SP magnum primers are fine in 9mm, but only for the load I worked up. For any other powder, I would go through the process all over again just to be sure. I chrono'd the load, and shot it along with a number of others, and had a commercial load for reference (which was a bit over 1100 fps), and recorded as much data as I could that day (eventually the sun got to a position where the chronograph started spewing bad data).

At the risk of repeating myself, SP magnum primers are probably fine with other powders in 9mm, but I wouldn't assume it is without doing the appropriate testing. I would be much more cautious with a large caliber and a powder that only partially fills the case.

I went looking for SP magnum primers after getting back from the range, but the places I checked online were out of stock. I'd be perfectly happy finding some bricks at a decent price, and will be looking for some in the future.

 

[buck460XVR]

The reason for "magnum" primers in handgun loads is to ensure complete ignition with some hard to ignite magnum type powders. That's it. Period. Doing a test with easy to ignite non-magnum powders is not much of a test. Some powders actually do better with standard primers. Alliant distributor of 2400, a magnum powder, actually advises against the use of magnum primers as it can lead to higher ES and SD numbers. While some folks tend to think the primers themselves are adding power to the ensuing burn, it in itself is not the primary factor. The slight increase in velocity or pressure from the use of the magnum primer is more likely due to more efficient burn. Winchester does not make large pistol magnum primers and they are safe and work well with all powders.

 

[JJFitch]

So just when you thought it safe to get back in the water.


What do you do when the publish load data for a rifle cartridge says use Pistol primer?


Yes, obviously I wouldn't ask if there wasn't, there is at least one.
https://load-data.nosler.com/load-data/458-socom/

Well there ya go, the exception! Thanks for the update!

The WLP is considered a "magnum" primer and the cup may be hard enough to prevent slam fires!

I think I'd do a little research before reloading this for an AR!

Smiles,

 

[Metal God]

10-ish years ago I bought Win LP primers and they said for standard and magnum loads .

 

[mmb617]

Just to add some more controversy to this discussion I ran some tests yesterday with the powders reversed. Last time I used Titegroup for the 9mm and CFE for the .45 so this time it was 5.1 gr CFE with 115 gr FMJ in 9mm and 4.4 gr Titegroup with 230 gr FMJ in the .45.

The main takeaway for me was that with either powder the velocities were virtually the same in the 9mm regardless of whether standard or magnum primers were used.

But in the .45 both powders produced significantly higher velocities with magnum primers. The increase was between 50-75fps higher with the magnums. I can only assume that is due to the difference in case fill % in the larger .45 cases. Perhaps the magnums do a better job of igniting the powder in low fill situations?

At any rate, since I'm not loading anywhere near max charges I will feel comfortable substituting magnum primers for standard ones in the future if that's all I can get. But I'm not saying anyone else should do that just based on my observations.

If nothing else this has been a fun excuse to play around with my chrono. I just bought a new (cheap) pistol rest for just that work and it's made me much more confident that I won't shoot the chrono as my groups are much smaller now.

 

[Laphroaig]

I need to correct my numbers , They only reach 40k psi so not to different then some magnum pistol cartridges . I guess magnum pistol primers would work for those loads .

Large rifle and pistol primers have different depths, so they are not interchangeable. A LRP would sit proud in a case designed for LPP and would not be safe in a free-floating firing pin rifle such as an AR-15.

 

[Coldfinger]

I see that this thread is a few months old. I feel its relevant considering this shortage is worse than the '08 craze. I recently loaded some 124gr Berry's HP over 5.5gr of #5 using magnum SPPs. I'll test fire them Tuesday. Going to load some 40 tonight using magnum primers as well. Now to revitalize this thread... Do any of you have experience using small rifle primers in lieu of small pistol in 9mm or 40? I've come across several thousand (8-10) boxes of small rifle but can't get any small pistol. Thoughts are appreciated. Or we can move to a new thread and I apologize for hijacking the thread.