.357 Magnum Primers question

[Sparkola24]

Do I have to use magnum primers to load .357 magnum rounds? I planned on using CCI regula small pistol primers and a 158 grain SWC lead bullet. I have 3 powder choices..231, Unique and 2400.

[Bill Steele]

Do I have to use magnum primers to load .357 magnum rounds? I planned on using CCI regula small pistol primers and a 158 grain SWC lead bullet. I have 3 powder choices..231, Unique and 2400.

Regular primer will work with all those powder choices.

[Sparkola24]

That'll do.

If it matters...any opinions on powders? I am shooting these out of a Ruger GP100 4.2 inch.

[Bill Steele]

That'll do.

If it matters...any opinions on powders? I am shooting these out of a Ruger GP100 4.2 inch.

W231 is my favorite for light loads in this caliber and bullet weight.

Unique is a gooid middle group, but not my favorite overall.

2400 is my all time favorite for full .357 Mag loads.

[huckberry668]

usually you'd use magnum primers for higher load density and slow burning 'ball powder' like 2400. But 2400 wouldn't be a good powder for SWC lead bullets . I don't see a recipe for 158 SWC lead for 2400. I suspect it wouldn't burn clean even with magnum primers.

Unique is a flake powder and tops out at 6 grains so regular primer would do. 3 to 5 grains of 231 won't need mag primer even tho it's a ball powder.

[j.primo]

I always use non magnum primers. I've used standard primers with TG and currently using Unique on my .357 mag loads.

[Beelzy]

That'll do.

If it matters...any opinions on powders? I am shooting these out of a Ruger GP100 4.2 inch.

Ditch the 2400 powder, as there will be a lot of unburned kernels with a short
barrel.

[ireload]

I've been using Unique for my .357 mag loads. Between mid to max powder charge. I was using 2400 many years ago but would experience some unburned powder even with mag primers topped off with jacketed bullet. In my opinion 2400 really shines out of a 6" barrel. You get a complete powder burn and higher velocity. With lighter .357 mag loads I use W231.

[bandook]

Ditch the 2400 powder, as there will be a lot of unburned kernels with a short
barrel.

If you're in the sf bay area, ditch the 2400 my way. We can make an equitable exchange for Trail Boss if you wish.

[Bill Steele]

If you're in the sf bay area, ditch the 2400 my way. We can make an equitable exchange for Trail Boss if you wish.

Beat me to it. Dang.

[AJD]

usually you'd use magnum primers for higher load density and slow burning 'ball powder' like 2400. But 2400 wouldn't be a good powder for SWC lead bullets . I don't see a recipe for 158 SWC lead for 2400. I suspect it wouldn't burn clean even with magnum primers.

Alliant actually recommends standard primers with 2400. So does Speer in their manual. Elmer Keith also swore for years about using standards over magnums with 2400.

2400 and a lead SWC bullet is a good combination as long as you get the right bullet fit and hardness. Lyman has data for it and I know plenty of people who have used cast bullets with 2400 and had excellent results. Elmer Keith used lead bullets and 2400 quite extensively.

[bohoki]

i always use small rifle primers for all small primer use they cost the same and work the same and i wont accidentally load up some 223 with small pistol

[Sparkola24]

Beat me to it. Dang.

Sorry guys, I live in Missouri, and can use it in my .44 mag loads.

[Cowboy T]

usually you'd use magnum primers for higher load density and slow burning 'ball powder' like 2400. But 2400 wouldn't be a good powder for SWC lead bullets . I don't see a recipe for 158 SWC lead for 2400. I suspect it wouldn't burn clean even with magnum primers.

Unique is a flake powder and tops out at 6 grains so regular primer would do. 3 to 5 grains of 231 won't need mag primer even tho it's a ball powder.

Actually, 2400 burns very well with regular primers, which is all I use. Where you need magnum primers is H110 and its twin, W296. That's because H110/W296 is harder to ignite and thus takes a hotter flame. 2400, by contrast, lights very easily. Same with the faster powders like W231, Titegroup, Bullseye, Clays, Unique, etc.

The round you're using has no bearing on whether you need magnum primers. It's the powder, not the round, that makes that difference. My standard load for .357M is 13.0gr of 2400 under a 158gr cast boolit sized to my gun's chamber, using regular small pistol primers (brand doesn't matter--I've tried most of 'em out here). My ".45 Colt Magnum" load also uses a very healthy dose of 2400 under a 255gr cast boolit, lit with a standard large pistol primer.

[huckberry668]

Alliant actually recommends standard primers with 2400. So does Speer in their manual. Elmer Keith also swore for years about using standards over magnums with 2400.

2400 and a lead SWC bullet is a good combination as long as you get the right bullet fit and hardness. Lyman has data for it and I know plenty of people who have used cast bullets with 2400 and had excellent results. Elmer Keith used lead bullets and 2400 quite extensively.

Actually, 2400 burns very well with regular primers, which is all I use. Where you need magnum primers is H110 and its twin, W296. That's because H110/W296 is harder to ignite and thus takes a hotter flame. 2400, by contrast, lights very easily.

The round you're using has no bearing on whether you need magnum primers. It's the powder, not the round, that makes that difference. .

Elmer Keith can say what he wanted and I don't doubt 2400 burns well with regular primers. My experience with high case density fine ball powders loads like 296, H110, AA#7 & 9 in magnum rounds is to use magnum primer for reliable and cleaner burn. Plus, 2 other guys said 2400 doesn't burn clean in their experience.

Bullet does make a difference. My 40sw loads for example, 6 grs of AA#7 would smoke badly and spray unburn powder all over me with the much softer 180gr Rainier copper plate bullets. I tried mag primer and it burned clean but accuracy got real bad. 9 gr of the same AA#7 behind a 180gr Zero FMJ burns clean as a whistle with regular primer. All I'm saying is, if it doesn't burn clean, reduce the load and use mag primer for a change.

It's great we can actually share personal experiences here. I'd recommend the less experienced reloader to go by the book when they ask for input. My Speer #12 and Laser-Cast reload manuals call for mag primers for 2400 on all 357mag loads copper jacket or cast.