Standard sp primers for magnum loads? [Archive] - Glock Talk


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04-29-2010, 20:51
I have settled on 2400 as the powder to load mid range to hot .357 loads (231 for low end). I have a couple of thousand small pistol primers that I bought for .38 special and I was wondering if I can use them for medium to hot .357 loads... I am thinking that maybe they'll leave some unburnt powder.... What is your experience?

04-29-2010, 23:29
Actually, my Speer manual warns against using magnum primers with 2400 powder. It seems Alliant reformulated 2400 to burn somewhat faster than the older Hercules brand. They say using magnum primers can raise pressures to possibly dangerous levels.
I'd stick to standard primers for all loads using Alliant 2400.


04-30-2010, 01:41
Yeah, you do NOT need mag primers w/ 2400. Even in max loads in the 44mag, I use std primers.

04-30-2010, 07:15
As has been said one does not need to use magnum primers with 2400. Some say the use of magnum primers with 2400 will degrade accuracy and raise pressures. In my experience pressures WILL be raised but accuracy may or may not be degraded. Different loads/guns may show better accuracy with the use of magnum primers. If the data you use shows standard primers and you care to try magnum primers start LOW and work up carefully.

04-30-2010, 08:54
Thanks for the info guys! I do not know what I would do if I did not have this resource.....

Zombie Steve
04-30-2010, 10:45
I usually use standard primers with 2400, but for a while there, all I could find were magnums. I still load my hot 158 grain XTP load with a magnum primer. When I worked them up, I took it all the way to max with no pressure signs. My accuracy load was somewhat less, so I stick with that.

FWIW, I went from Lyman 49 and again, the 158 grain XTP, 2400 and CCI 550 primers. At first I was using winchester brass and the accuracy load was 14.8 grains (it shows max at 14.9 with a mag primer). I wound up getting a bunch of starline brass and when I worked back up, the accuracy load was at 14.6 grains with similar speeds. Thicker brass, I guess. I never shot them hotter than that once I saw what it did on paper.

Anyway, back to your point, standard primers work well with 2400. If you're seeing unburnt powder, consider a little stronger roll crimp.

Zombie Steve
04-30-2010, 10:47
I'm going to add I'm coming up with the powder weights off the top of my head... I'm not near my data and could be wrong. Consult Lyman 49 for details.