Author Topic: Mag vs Standard Primer  (Read 453 times)

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Offline charles p

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Mag vs Standard Primer
« on: May 16, 2007, 10:58:37 AM »
A friend made the comment recently that he uses mag primers with ball powders, in non-mag cases.  I think he was discussing 7mm-08.  Ever heard of this? 

Offline The Sodbuster

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Re: Mag vs Standard Primer
« Reply #1 on: May 16, 2007, 12:28:44 PM »
The Speer #13 manual frequently recommends magnum primers for ball powders (at least for some of the calibers I reload for).  I tried the same load in .223 Remington, one with CCI 400 primers (small rifle) and the other batch with the recommended CCI 450 primers (small rifle magnum).  I couldn't see any difference in accuracy.  I don't have a chronograph.  This was during warm weather.  It might make more of a difference in very cold weather.

Offline Old Syko

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Re: Mag vs Standard Primer
« Reply #2 on: May 16, 2007, 03:43:20 PM »
Your friend is correct in expressing a need for mag primers with ball powders.  Ball powders, especially when used in high volume cases, usually need the extra boost of a mag primer to achieve consistent ignition.  This can be shown more clearly when doing comparisons over a good chronograph.  Check this link http://www.jamescalhoon.com/primers_and_pressure.php for more useful info on primers and pressure.  I burn a lot of WW748 in various calibers and find the mags to be a very important part of the recipe.