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Standard vs. Magnum Primers

Discussion in 'Ammunition & Reloading' started by Modeler, Feb 20, 2013.

  1. Modeler

    Modeler Molalla, Oregon Soccer Fan

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    In these times of primer shortages, I have to ask:

    What's the difference between standard and magnum primers?

    Is it ok to use magnum primers in standard loads like 9mm or .40?

    Is it ok to use standard primers in magnum loads like .357?
     
  2. ma96782

    ma96782 Vancouver, WA Well-Known Member

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    A good reloading manual will spec a standard or magnum primer, depending on the cartridge, powder and/or bullet being used. For liability sake I can only say to use what the manual says to use. Now, that being said you control the process, never start with the hottest load mentioned in the books. Start low and work your way up. Watch for the signs of overpressure. If you are going to replace a magnum for standard primer, lower your powder charge a bit to compensate.

    From the Speer Manual #10

    Run your tests and choose what YOU like.

    And, the various manufacturers can and will change things up (chemical mixes, materials specs., etc.......) to suit their own criteria. So, don't assume that one brand can just replace another either.

    Aloha, Mark
     
  3. Trailboss

    Trailboss Vancouver, WA Well-Known Member

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    Yes to both, but you have to start low and work your loads up again. The different primer heat can affect pressure so start slow and find the perfect load.
     
  4. nwdrifter

    nwdrifter troutdale oregon Active Member

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    i have never noticed a difference and use mags a lot..
     
  5. Modeler

    Modeler Molalla, Oregon Soccer Fan

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    Thanks for the info. I have used magnum primers in standard 9mm loads and they seemed to work fine, now I'm getting ready to load .357 magnum in the coming months and I was curious to know what the difference was.

    Thanks!
     
  6. SinisterSouthpaw

    SinisterSouthpaw SW WA Active Member

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    I ran out of small pistol magnum primers during the last Obama panic and had to use standard primers in my .357 loads. These loads are just for paper punching and are lighter than some folks may be using in the same caliber. Shooting 158 gr. JHP or plated FNs propelled by Lil' Gun powder in various doses, I noticed no difference on target. When mag primers became available again, I bought some, since I also carry a magnum caliber and I want that gun to light up the load strongly. Since I only use the standards for the target guns I have plenty of primers to get me through this current silliness.
     
  7. rrojohnso

    rrojohnso Vancouver, WA Member

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    This leads to a great question regarding Rifle primers - same thing: Using a Mag primer in a lg rifle primer pocket. Has anyone had any experience in using a Mag primer with a mid to slow burning powder in a .308? I asked one loader, and he said you'd never notice a difference. As one to be skeptical, it seems a really hot primer (mag) and a slower burning powder could create a smoother pressure curve, which would potentially mean softer recoil, but also greater consistency down range? Thoughts?
     
  8. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    Or a lot of burning powder ejected from the muzzle for a nice flash.

    As I understand the whole process, the primer's job is to merely light off the powder column in the case. Some powders, notoriously ball powders, are hard to light. Most slow powders are stick and easier to light. I'm not sure that the primer is really part of the recoil equation though.

    A load where the primer characteristics and the powder characteristics are matched to bullet and barrel will yield the best accuracy. Some do it with magnum primers and some with standard. All depends on how you adjust the rest of the variables.
     
  9. rrojohnso

    rrojohnso Vancouver, WA Member

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    Makes sense. Thanks DS - Also, for the record, the SS Pins do a magnificent job at cleaning primer pockets and brass.