Magnum primers vs standard primers

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  • PeterJ

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    Can I substitute a magnum large rifle primer for a standard large rifle primer? I would like to use them in 6.5 Creedmoor over Varget powder.
     

    gwpercle

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    Can I substitute a magnum large rifle primer for a standard large rifle primer? I would like to use them in 6.5 Creedmoor over Varget powder.

    Yes , but drop the powder charge back a grain , especially if you are loading at maximum charges , just to make sure you don't bump up pressure . Shoot a few groups , look for excess pressure signs and adjust load as needed .
    A few years ago the primer shortage had many using magnum primers when it was all they had/could get . It bumps pressures up a little so the caution to drop back and work up .
    Gary
     

    gwpercle

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    What Gary said,You should only get about 19feet more per second mag. vs. std. primers

    Only 19 fps , yes that sounds correct ...I knew it wasn't much but some reloader's just went off the deep end claiming several hundred fps and horror stories of excess pressure exploding rifles by simply switching to magnum primers .
    Thanks for the input .
    Gary
     

    mickey

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    Thickness in cup between both mainly.
    Most don’t understand the difference in ignition between manufacturers.
    Some brands are much hotter/cooler than others
     
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    mickey

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    A good write up that helps answer your question
    http://bulletin.accurateshooter.com/2017/04/ultimate-large-rifle-primer-shoot-out-16-types-tested/

    And this one has examples of flash

    https://www.6mmbr.com/primerpix.html


    b9cbbd1d5d8bd7cc8cb791eaef1750ee.jpg
     
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    mickey

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    Yes , but drop the powder charge back a grain , especially if you are loading at maximum charges , just to make sure you don't bump up pressure . Shoot a few groups , look for excess pressure signs and adjust load as needed .
    A few years ago the primer shortage had many using magnum primers when it was all they had/could get . It bumps pressures up a little so the caution to drop back and work up .
    Gary

    Nope
    I don’t agree.
     

    mickey

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    I really enjoy reloading but it can be so inexact.
    Whatever you do, tread cautiously and amp up slowly.

    I have seen 100fps muzzle velocity swing just between lot numbers (same powder charge) of h4350 in 6x47 loads.
    A lot of misinformation out there.
    Just because it says magnum don’t mean it goes faster.
     
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    beauxdog

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    We have this question all the time. What we time folks is magnum doesn’t necessarily mean hotter.
    Mickey has loaded more primers than any ten regular shooters, he speaks from years of experience.

    Bryan
     

    mickey

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    We have this question all the time. What we time folks is magnum doesn’t necessarily mean hotter.
    Mickey has loaded more primers than any ten regular shooters, he speaks from years of experience.

    Bryan

    /\
    Bryan, The level of knowledge that you have standing behind the counter of your shop Is second to none. I send those that are lost there often for guidance.
    Between yourself and the xmeister, there is not a reloading question that is not in your wheelhouse.
     

    340six

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    Only 19 fps , yes that sounds correct ...I knew it wasn't much but some reloader's just went off the deep end claiming several hundred fps and horror stories of excess pressure exploding rifles by simply switching to magnum primers .
    Thanks for the input .
    Gary

    That is even more than what was recorded when we tested some custom rounds I made up years ago. I wouks, say on some case's it just cleaned up the loads and made them more accurate. Shooting on a day with different water did more.
    In one case a low power load of Varget and 4895 the magnum primers in 30-06 did just that. The mag used gave a cleaner burn and also made them more accurate. It was a,win win
     

    Gator 45/70

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    That is even more than what was recorded when we tested some custom rounds I made up years ago. I wouks, say on some case's it just cleaned up the loads and made them more accurate. Shooting on a day with different water did more.
    In one case a low power load of Varget and 4895 the magnum primers in 30-06 did just that. The mag used gave a cleaner burn and also made them more accurate. It was a,win win

    Yeah,Years ago someone posted their results on BS, Was that you by chance?
     

    340six

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    Yeah,Years ago someone posted their results on BS, Was that you by chance?

    Yes it was me. Also looks like spell check killed my reply and changed some and not others.
    I my case low power loads in 30-06 showed more variance in weather than primers.
    In cold weather where temp sensitive powder was used with mag primers they helped a lot. Also cleaned up the burn as,well as made more accurate. In my case we tried them due to low case fill instead of using a filler as some do. FYI some cast bullet guys use a filler on top the powder
    To get better ignition with things like Dacron. I am not a fan of doing that.
    Also reading up looks like Military Primers sold by CCI for 5.56 and 7.62x51 guys use in semi auto are Magnum Strength but with a thicker cup to prevent slam-fire.
     
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