I am sure this has been asked. I have large and small pistol primers and I am going to load 357mag. I have heard of people using regular primers versus small magnum primers. Some people say that you don't go by the headstamp but by the powder you are loading. I am planning to load 700x with a Berry copper plated bullet in starline brass. Will it work with ordinary primers?
Question about primers in 357mag
- Thread starter Scuba2do
- Start date
Register to hide this ad
As a rule, you're never wrong to use a magnum primer, but not all loads in the .357 require it. The only size that fits the .357 Magnum is the small pistol primer (you allude to have both large and small - small is it). So the question is standard or magnum small pistol primer.
If I load down the .357 to .38 special velocities and pressures, I use a standard primer. For full house magnums, in which I nearly always use only 2400, I use a magnum (though 2400 lights so easily that a magnum primer really isn't necessary).
If I load down the .357 to .38 special velocities and pressures, I use a standard primer. For full house magnums, in which I nearly always use only 2400, I use a magnum (though 2400 lights so easily that a magnum primer really isn't necessary).
jepp2
Member
From a need standpoint I always consider a magnum primer strongly recommended for H110/W296. Just a hard to light powder.
After that, I always look at what was used in the load development of the source I am using. I just checked the Hodgdon on-line data and saw they used Win SPM on all their powder. Mostly I am interested in knowing if I intend to use a magnum primer where the load was developed with a standard primer. Could cause higher pressure.
Just for general information, Remington says not to use their 1 1/2 primer in 357 Mag loads. So if I am loading near the upper pressure end, I use the 5 1/2 primer.
[URL=http://s860.photobucket.com/user/jepp2/media/Rem15Warning-2.jpg.html]
[/URL]
After that, I always look at what was used in the load development of the source I am using. I just checked the Hodgdon on-line data and saw they used Win SPM on all their powder. Mostly I am interested in knowing if I intend to use a magnum primer where the load was developed with a standard primer. Could cause higher pressure.
Just for general information, Remington says not to use their 1 1/2 primer in 357 Mag loads. So if I am loading near the upper pressure end, I use the 5 1/2 primer.
[URL=http://s860.photobucket.com/user/jepp2/media/Rem15Warning-2.jpg.html]
[/URL]Rickster49
Member
mag primers for 700-X?
You would never need magnum primers for ignition purposes with 700-X. It burns readily with the mildest primers. The only purpose I could envision using mag primers in the 357 would be for full power banshee screamer loads which could cause primer flow. Unlikely with any recommended 700-X loads. An excellent powder for many handgun applications by-the-way. One of my very favorites....
You would never need magnum primers for ignition purposes with 700-X. It burns readily with the mildest primers. The only purpose I could envision using mag primers in the 357 would be for full power banshee screamer loads which could cause primer flow. Unlikely with any recommended 700-X loads. An excellent powder for many handgun applications by-the-way. One of my very favorites....
Seems like I have read that fast burning powders there really is not too much concern as one would have with slower burning powders I also have some Trail Boss I was going to use as well. Thanks for the recommendations.
Some loads require magnum primers
Some powder need to have magnum primers like 296/110.
I use 2400 in my .357 load that don't need a magnum primer.
You can use magnum primers even on loads that don't require it if you back off the powder charge a few tenths of a grain and work the load back up.
Your loading manual tells what primer is used. It's funny that my Lyman 49th says to use magnum primers with all .357 loads. Easier for them, probably. It ain't necessary with all powders.
Some powder need to have magnum primers like 296/110.
I use 2400 in my .357 load that don't need a magnum primer.
You can use magnum primers even on loads that don't require it if you back off the powder charge a few tenths of a grain and work the load back up.
Your loading manual tells what primer is used. It's funny that my Lyman 49th says to use magnum primers with all .357 loads. Easier for them, probably. It ain't necessary with all powders.
Last edited:
Hodgdon also list Mag primers with anything "named" magnum. I called and asked about that and they said just for consistency. For example HP38/Win 231 does not need a Mag primer to burn correctly.
But for the OP the 357 uses a Small primer (actually when it first came it did use a large primer but that was many moons ago)
I do not use 770 x so can not say,
But for the OP the 357 uses a Small primer (actually when it first came it did use a large primer but that was many moons ago)
I do not use 770 x so can not say,
