Quick .357 Magnum Load question

[Johnny B]

So, since I am the proud owner of a new set of .357 Mag/.38 Spl. dies, along with some new powders and primers, I have a quick question. For the hotter Magnum loads, most likely pushing 158 grain LSWC's or JSP's of the same weight, I was planning on using Alliant 2400 and CCI magnum small pistol primers. Are the primers too hot for this powder? Should I just use a standard small pistol primer to avoid excessive pressure? Thanks in advance for your help, it's much appreciated.

 

[FM12]

Do you have a loading manual? If so, which one?

 

[Johnny B]

I have a couple: Lee and Speer. The Alliant load data itself seems to say that there's nothing wrong with using magnum primers, and their data recommends Federal 200's, which from my understanding are slightly hotter than the CCI primers. This is just one of those questions I ask as a precaution before I start working up a load.

 

[JackOfAllTradesMasterAtNone]

You do need to go by the specs in the reloading manuals.

That said, I've referenced my notes and at least one of my manuals, and yes, for 2400, H110, W296, even AA#9, you do want a magnum primer. That primer is certainly not too hot for A2400.

That being for a jacketed bullet in the weight you've specified.

For lighter powder loads for a LSWC, you don't really need the magnum primer, and 2400 certainly isn't the best choice for light loads. But if I was loading LSWC as hot as I dare, then I'd use a standard primer. Elmer Keith did it with great success.

-Steve

 

[ArchAngelCD]

Many reloaders state that 2400 doesn't need a Magnum primer but I always use Magnum primes especially since I use H110 or W296. Those powders are hard to light and I get better results with Magnum primers.

If you are going to use Magnum primers make sure you start at the Minimum charge and work your way up checking for any signs of excessive pressure. Also, I wouldn't push Lead bullets too hard since you can have a Leading problem. I wouldn't push them over 1200 fps. I don't push lead over 1100 fps and haven't had Leading problems.

 

[Cosmoline]

I don't know how much it actually matters. I know very experienced handloaders who've used only standard primers. IIRC that includes EK himself. The magnums were around before there were magnum primers.

The only danger issue is if you use a max load designed for standard primers and use magnum.

 

[Johnny B]

Thanks folks. I'll start with starting loads and be more cautious and attentive when building up the load. I'm still pretty new at this, so I'm not much of a daredevil when it comes to super-hot loads. I usually keep the charge well below the max. It's more economical that way, too.

Good point about leading, ArchAngel; for the lighter loads with lead bullets, I will just go with a faster burning powder and a standard primer. I'm none too enthusiastic about spending a chunk of my day scouring lead from the bores of my guns.

 

[JackOfAllTradesMasterAtNone]

Cosmoline, You made me re-read my own post!

I had typo'd what I meant to say... Corrected now.

-Steve

 

[Ben Shepherd]

I use magnum primers exclusively with 2400. I've several manuals on hand and they are split on the issue of standard or magnum with this powder.

I tried standard primers with 2400 as speer currently reccomends. Didn't work out. Cold weather shooting with standard primers gave me very unacceptable results: unbrned powder in the barrel, WILD velocity swings, even percieved recoil and muzzle blast were all over. Back to magnum primers, no problems since.

As for charge weights: Start at around 13 grains of 2400 under a 158 grain slug, work up from there. If you push past 14 grains you're pushing the upper limits of every current manual I know of. So if you go higher be careful. And you better be chrono mapping by that point.

 

[Ben Shepherd]

Johhny B: Check your PMs.

 

[Kevin_G]

Max for 2400 under a 158gr bullet

My Sierra manual lists the starting load for 2400 (158gr bullet JSP) at 14.0 gr. Max goes up to 15.0. That's with CCI 550 primers. I haven't shot any of my own .357 reloads yet but have a batch loaded from 14-15 grains at .2 gr increments. Plan on testing them out tomorrow...I'll let you know how it turns out.

 

[Powderfinger61]

I know your talking mostly about 2400 powder, but just to give you another variable. Ive had great success with 3 grains of Bullseye for the .38 (mild target load-cast wad cutter) and 6 grains of Bullseye for jacketed .357 loads. All with standard primers. You should get approximately 1166 .357 loads with the Bullseye powder.

 

[rcmodel]

Why stress a gun with Bullseye powder trying to get Magnum velocity plinking loads.

The pressure spike is very violent with hot-loaded Bullseye.

Unless you are loading for a 2" .357 Snubby, there are a lot of better & more suitable powders for Magnum loads that give much better velocity at less peak pressure.


rcmodel