What are Magnum Primers used for?
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Hondo 60
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Magnum primers are used mainly to ignite slower, hard to ignite, powders.
Just follow the data you use.
It'll say if they used Magnum primers or not.
Powders from Hodgdon will use them when the cartridge name includes the word "Magnum".
Like .32 H&R Magnum, .327 Federal Magnum, .357 Magnum, 41 Magnum, 44 Magnum etc, etc.
Just follow the data you use.
It'll say if they used Magnum primers or not.
Powders from Hodgdon will use them when the cartridge name includes the word "Magnum".
Like .32 H&R Magnum, .327 Federal Magnum, .357 Magnum, 41 Magnum, 44 Magnum etc, etc.
Basically, magnum primers are for igniting harder to ignite powders, for whatever reason. Many slow burning powders are harder to ignite, H110/W296 for example and lower temperatures will affect some powders ability to burn. Just because a cartridge has a "Magnum" designation does not mean they require a magnum primer, but some experiment and have found magnum primers to perform better for a specific load in their specific guns. About 95% of my magnum handgun loads use standard primers.
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Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...
earlthegoat2
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Some load data publishers will provide the primer manufacturer number. I just looked at Speers load data page for .458 Lott and it specified a Federal 215 primer. It doesn’t say this anywhere but a Fed 215 primer is a large rifle magnum primer. Just like a CCI 250.
Hondo 60
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Just loaded 357s last night.
Data from Lyman's 3rd Cast Bullet Manual called for Winchester Small Pistol Magnum primers with W291.
I also had a conversation with Johann, a ballistician with Hodgdon & asked him about primers.
He said they specified Mag primers because he felt too many reloaders used mag if the title of the cartridge had the word magnum in it, whether the powder required it or not.
He was just feedin' the masses.
edwardware
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For instance: with a 375H&H case full of 4831SC, an LRP results in a barely perceptible click. . BOOM, and the occasional failure to fire. An LRPMag results in an instant BOOM, 100% of the time.
I've measured a small reduction in ES in .357Mag with H110 with SPPMag, but it was minimal.
My takeaway: if your powder/volume combination doesn't need the Magnum primer, it won't make much difference other than a little velocity/pressure. If you do need it, you really do need it, especially in the cold.
I've measured a small reduction in ES in .357Mag with H110 with SPPMag, but it was minimal.
My takeaway: if your powder/volume combination doesn't need the Magnum primer, it won't make much difference other than a little velocity/pressure. If you do need it, you really do need it, especially in the cold.
I think it is more important with rifle cartridges than handgun. The rule of thumb with rifles is anything over 60 gr of powder should probably use magnum primers. But as always there are exceptions to every rule. I loaded for 300 WSM for a while and started using magnum primers. But during a component shortage couldn't find any so I used standard primers. It made zero difference in velocity or accuracy so I just kept using standard primers. The 300 WSM is just barely over 60 gr and that is probably why. In another case that needed 70-80 gr of powder it might not have worked.
A lot of guys use magnum primers in cases that hold much less than 60 gr of powder and claim a bit better accuracy. Normally using them in smaller cases doesn't hurt anything. You may get 10-20 fps, more speed and if you're already pushing the envelope you could get a load a little too hot.
A lot of guys use magnum primers in cases that hold much less than 60 gr of powder and claim a bit better accuracy. Normally using them in smaller cases doesn't hurt anything. You may get 10-20 fps, more speed and if you're already pushing the envelope you could get a load a little too hot.
spitballer
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There was a good article in Hodgdon's Annual Relaoding Manual that covered this very subject a couple of years ago. Author by the name of Pearce as I recall. Takeaway was magnum for ball powder and regular for stick, but no hard and fast rule. Since then I've always used regular for stick powder.
At one point several of the reloading manuals cautioned that Magnum primers were essential with H110. Most have dropped that warning. I still go by it though.
I have also found that in lighter loads where the powder takes <50% of the space a magnum primer will more consistently ignite the powder.
I have also found that in lighter loads where the powder takes <50% of the space a magnum primer will more consistently ignite the powder.
AJC1
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The best answer is testing all options in your shooting environment. Some powders are well published to do better with mag primers like h110. Some like imr 4227 seem to give better numbers in my experience when using mag. Some people will say 2400 needs a mag and others say no. Rules of thumb help when giving recommendations but only testing give absolute truth.
hossfly
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Some powers, usually ball powders, tend to get more uniform ignition and burn with them.
I find that VERY hard to believe. I've got a stack of manuals and data books about four feet high. I have yet to see one that didn't recommend using magnum primers in the appropriate situation.
748
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As far as I can tell they are good for is causing a larger standard velocity deviation.
I largely stopped using "magnum" primers shortly after I got my chronograph and gave up trying to buy them all together back during the great primer shortage.
I largely stopped using "magnum" primers shortly after I got my chronograph and gave up trying to buy them all together back during the great primer shortage.
fxvr5
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You need to expand your reading list.
Eddietruett
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I make it real easy on handgun loads. I use magnum for everything. Have been doing so since the last primer shortage and never had a minutes problem. I use Federal exclusively since I have a lot of revolvers with very light actions, and during the shortage all I could find was magnum small pistol. I've chronographed loads using both magnum and regular and there is hardly a difference even on the rabbit fart loads using 2.7gr of Bullseye. 90 percent of my shooting is 38 special using Universal primarily for mid range loads. I think and it could just be me that the magnum primers actually make most powders burn a little cleaner. I've also noticed the Winchester primers I see for sale now say for standard and magnum loads.
Obturation
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I only use mag primers if I have a choice, it simplifies my life. In some circumstances it's required and if you get to some high pressure loads, the material is thicker & harder to keep from pierced primers and other issues.
Use what works
Use what works
https://www.6mmbr.com/PrimerPix.html what does this do for you ?
Toprudder
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Regarding 2400 and magnum primers, Alliant data shows regular primers only. And then there is this that I found a couple of years ago:
Targa
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I don't load many different calibers and as of now I am only using H110/296 and Universal so I am just using magnum primers for everything.
wasa
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With one exception, I always follow what it says in my manual. My exception is ball powder in 7.62x54R. For some reason, I have had many issues with A2700, H414, and W760 (from memory - sorry if mixed up) with CCI, Federal, and Winchester LR primers. I would get incomplete combustion with the bullet lodged just downstream of the throat in my Mosin. Usually, a cleaning rod down the barrel would get the bullet out. Then I had to clean the gun of the powder crud. Posted on another forum where it was suggested to switch to LRM primers. Since then, never an issue and will use LRM primers for large capacity cases and ball powder.
Standard disclaimers apply.
Standard disclaimers apply.
Demi-human
maybe likes firearms a little bit…
This information can be found in the front section of the manuals that don’t tell you what primer to use...
Evidently you don’t use Hornady, Speer, Hodgdon online or Alliant.
Not looking and not seeing are not the same as not being in there.
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