Mag vs Standard Primers

[Pumah25]

I am reloading for 357 Mag 158gr JHP. I am not planning on making super hot loads. I have been told that I need the small pistol magnum primers. I have also been told that I do not need the mag primers if I am not doing "hot loads". Can someone shed a little light on this for me? I use Winchester Primers if that makes a difference.

[Larry Gibson]

Depends on the powder used. Some powders need the hotter flame of the magnum primer for consistent and reliable ignition.  Your Winchester primers will do for 99% of loading. If you are going to use the top end loads with H110 or 296, for example, then a hotter magnum primer is warranted.

Larry Gibson

[Bullseye]

I might be wrong, but I thought the 357 magnum was a round that almost books call for a magnum primer with any powder.  I thought Winchester only makes a magnum primer in the small pistol version and the reason they did was for the 357 magnum.  I might be dreaming though, it has been a few years since I fooled with the 357 magnum.

[jhalcott]

  Pumah, go with the primers that are listed in your manual. Some powders require the mag primer some don't. A magnum primer will raise pressures  with a powder that doesn't NEED one, BUT you can work up to a decent load with one using the powder. Just start low and work up. Accuracy may not be the best doing it this way though!

[buck460XVR]

  Pumah, go with the primers that are listed in your manual. Some powders require the mag primer some don't. A magnum primer will raise pressures  with a powder that doesn't NEED one, BUT you can work up to a decent load with one using the powder. Just start low and work up. Accuracy may not be the best doing it this way though!

+1...............go with what the manual says.

[Steve P]

Use the Winchester small pistol primers and you will be fine.  They are hot enough to prevent any detonation with low end book loads of H110 and 296.  They are not too hot to exceed pressures with book loads using other brand "standard" primers.   Since we have removed the dangerous "too hot" and "too cold" scenarios, you can get to reloading. 

I agree with the gentlemen above who state you have to follow the recipe in the book.  That is the safest and easiest way to learn to reload.  It will also get you 4-5 different brands of primers and many different one pound bottles of powder. 

If you are on a budget or want to stick with one brand of powder or primer, you either have to find the loads in a book, or question those with experience you can glean from.  In this case, I have loaded and fired 10s of thousands of 38s, 357m, and 357sm.  Your Winchester small pistol primers will work with any modern books loads and most old school loads. 

Steve