Anyone using Magnum primers

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Anyone using Magnum primers

Postby demo_450 » Thu Jul 02, 2009 11:49 pm

I used some magnum primers last weekend. no problems. no unburnt powder. Any thoughts?
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Re: Anyone using Magnum primers

Postby MudBug » Thu Jul 02, 2009 11:52 pm

I believe that the general difference between standard and magnum primers is the thickness/hardness of the cup, not the amount or formula of the material inside.

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Re: Anyone using Magnum primers

Postby Al in Mi » Fri Jul 03, 2009 2:31 am

I found this on the Highroad awhile back for cup thickness althou it doesn't cover all the brands,

In both of my FA 454's, the only primers that won't crater back around the firing pin with full house H110 loads, are the Remmy 7 1/2 and the Fed 205m, and according to this chart, they have the thickess cups of all.

How they generated the power rating factor numbers I don't know, guess you'd have to run your loads over a chrono and see if there was any velocity difference between them.
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Re: Anyone using Magnum primers

Postby pitted bore » Tue Jul 14, 2009 8:22 pm


Primers do vary in their "power" as well as thickness of cups. In general the magnum version of a manufacturer's primers is more "powerful" than the non-magnum version.

An excellent introductory article on primers, written by John Barsness, is here: There's really quite a bit of information in that article that is relevant to chosing a primer for reloading the 450B.

The list of primers in the link that Al in Mi posted from the highroad forum was generated on this web site: As the author and developer of the list indicates, the power scale is in relative DMS units ("don't mean squat").

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Re: Anyone using Magnum primers

Postby MOUNTIN DU » Tue Jul 28, 2009 7:22 pm

i know for a fact that when shooting primer powered rubber bullets in my handguns, there's definitely a difference between std & mag!

38spl case w/std primer = 350fps from 2.5" security six; chrony 3ft from muzzle
38spl case w/mag primer=500fps from 2.5" barrel
44spl case w/std primer = 300fps from 3" bulldog at 3ft
44spl case w/mag primer= 400fps from 3" barrel
...also a very noticable flash from cylinder gaps with mag primers.

There's some really good advise on this website... I'd follow their lead when experimenting; the ones that are still alive anyway! :lol:
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