Magnum Primers in Non-Magnum Cartridges?

y2k

y2k

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Is there a differnce in pressure or bullet impact etc.,? I`ve never noticed a difference down range for accuracy when use`in different brands of regular primers but now I`m going to use Magnum Primers basically because thats all the store had. Is there anything I should know? I`ll be using them in 308 Win and 45-70 Gov. Thank You for any help.:)
 
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y2k said:
Is there a differnce in pressure or bullet impact etc.,? I`ve never noticed a difference down range for accuracy when use`in different brands of regular primers but now I`m going to use Magnum Primers basically because thats all the store had. Is there anything I should know? I`ll be using them in 308 Win and 45-70 Gov. Thank You for any help.:)
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First off... mag primers have more fire comin outta them and WILL cause higher pressures. That said, stick an IF at the end of that... if you use the same amount of powder. I know of people who always use magnum primers for ball powder (as it is 'harder' to ignite) even if the data does not call for it... but naturally you have to carefully load up to a safe maximum... which may be well below what is called for with a standard primer. That said, I don't substitute willy nilly... period... if it calls for standard I use standard. The guys who do the testing and write load manuals know much more than I.

I'm trying desparately to find a series of pics from the net (maybe even this site?) that show photos of various brands and types of primers. Pretty amazing differences.
 
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Look at a bunch of different manuals, Speer for one, use mag primers with all ball powder. Mag primers are commonly used with slow burning powders as well in regular standard cartridges. Some pistol loads can boost pressure 5000PSI by switching to mag primers, but I've never heard of any real problems using them with rifle loads but would use caution with max loads.
 
A change of any component in reloading could result in dangerous pressures.
That's a big could and it's you and your rifle that potentially could be damaged, so perhaps a prudent restart to all load development is called for.
 
I use magnum primers in all my cartidges which are 7 mag,22-250 and 270. I would work up loads using them. I have never used standard primers and probably never will.
 
y2K,
Normally I will use magnum primers in any rifle load using ball powders.You won't go too far wrong using whatever they used in the data you select. Standard Winchester primers are pretty much "magnums" due to Winchesters habitual use of ball powders in their factory loads.
One place that I always get better accuracy with a standard primer than a magnum is in the .375 H&H. Although I have no idea why, groups always seem to shrink with the milder primer. Of course, by today's standard of case capacity the H&H is hardly a magnum at all. More like a standard.
 
I use a magnum primer in anything with 60 or more grains of powder, both 270's my son owned were way more accurate with 60 grs of H4831sc and a magnum primer than with a standard.
 
Lefty #### said:
A change of any component in reloading could result in dangerous pressures.
That's a big could and it's you and your rifle that potentially could be damaged, so perhaps a prudent restart to all load development is called for.
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This is very good advice from LD!
Usually standard primers will exhibit better accuracy than the magnum primers but there are times when a rifle will prefer the magnums, this is not unusuall. The fact that most precision calibers do not use mag primers should be a good indicator that they are not prefferd for ultimate acurracy, they are more "erratic" in their burning characteristics and only required when trying to ignite very large loads of slow burning powders.
bigbull
 
Some guys will use magnum primers if they expect to hunt in very cold conditions. I'm not sure if there is a "real world" advantage or not though.
 
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