Preferred powder for .357 Magnum/cast lead bullet loads

I find HP-38 the most accurate and it's very clean but you'll need something slower to get "true magnum" performance. Like 2400. But you can get a bigger bang. At maximum loads Unique will likely give the highest velocity. Few consider Unique "clean" but at maximum loads it's a lot cleaner than with light loads. Bullseye is really too fast for the .357. Titegroup I have little experience with.

I have used all of them except for Unique, which I think may be the best if you want to push things hard. I like Titegroup as a little goes a long ways and it meters well for me, also seems pretty clean.

Bullseye is great but can be dirty and I don't think is idea for pushing a .357 hard.

Unique. Of those mentioned it’s the best for a magnum load.

Of the powders you listed I have the best luck with Unique for magnum loads. As mentioned earlier, I get the "best" magnum loads with 2400.

get some 2400 or H110/win296 for max loads.

.

Gimme a U
Gimme a N
Gimme a I
Gimme a Q
Gimme a U
Gimme a E

What’s that spell?

FUN with mid to upper range revolver loads .

Stay safe.

derek45 said:

get some 2400 or H110/win296 for max loads.

.

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Where?

I'll give you one guess what I would recommend....

I don't load for .38/.357 any longer, but when I did, 99.9% of my handloads got Unique. If you really want Magnum power, then step up to 2400, IMR4227, or W296/H110... but Unique will get you 80% there.

Of the 4 powders you list, only Unique should be considered for heavy loads in any event.

Unique

For full power magnum loads in a 357 Magnum revolver, I use W296/H110 powder.

I used 2400 back when it was made by Hercules and I'd get a bunch of unburned kernels left over. Maybe Alliant has fixed that. I've not used any 2400 since the 1980's.

I load mid range loads with Unique to about 950-1000 fps in a four inch barrel 357 Magnum revolver. Zippy enough for me and not hard on the hands and wrists.

W231/HP-38 would be a good alternative.

I do not like Titegroup. Too touchy for my liking. Bullseye is a great target powder, not great for pushing bullets to magnum levels in my opinion.

Clean shooting is a relative thing. If you shoot a gun, it needs to be cleaned afterwards. If you want to see dirty, shoot some black powder guns.

If you have hard cast commercial bullets you need to push them to magnum pressures in order to obdurate their base when shot to avoid leading as hard cast with light loads usually lead the barrel excessively. I prefer to load 158 gr hard cast LSWC commercial bullets with slower powders and like AA9 or 2400. 12.0 to 12.2grs of AA9 will push158 gr SWC hard cast bullets out the muzzle of my 4" barrel S&W 66 at around 1,240 fps as will 13.0 to 13.5gr of 2400, a load velocity that is typical for a factory 158 gr JHP .357 mag. Remember that you will get higher velocity with a lead bullet than a jacketed bullet with the same powder charge as the bullet has less resistance in the barrel and a full grain less charge will usually throw the lead bullet as fast as a jacketed bullet with the heavier charge.

For .357 mag loads with 158gr cast bullets using Unique my loads are usually at a more modest velocity of around 1,000 fps. To avoid leading I'll use the Missouri softer .38 spl 12 BNH bullets, Hornady or Speer 158gr swaged bullets behind 6.0gr of Unique.

J-Bar,
I would go with Unique as well, but mostly because I am most familiar with that powder out of the 4 you listed.
I was looking at the Alliant Unique site and it sure looks like they have toned down their loads. I will have to look in my manuals later to be sure.
https://www.alliantpowder.com/reloa...owderlist.aspx&type=1&powderid=3&cartridge=28

I was actually looking at doing he same thing only with Universal powder. 6.2 grains (Max load) is supposed to have a velocity of 1247 FPS out of a 10” test barrel.
The Alliant site states that 7.7 grains of unique will give you 1,040 FPS, but doesn’t give a barrel length.

I plan to use Bear Creek Supply molybdenum coated 158 grain RNFP bullets.

Unique is fully covered. I use it occasionally for .357 mid-power cast loads, but prefer HS-6 which is not on your list and a bit hard to find right now. Recently I've been playing with Power Pistol as I got some random lots at auction and want to use it up. Works very well in rifle-cast-158 loads. My 6" revolver hates it.

I did work up HP-38 to max and found it rather "blasty" and inaccurate in .357. It did very well in .38+p however. I got some leading also, but that may have been a bullet issue rather than anything to do with the powder choice.

Give you a few options here, as you never know what you may find these days. Full power hardcast performance optimum powders that I have personal experience with: Blue Dot, 2400, IMR4227, H110/W296. Some others that will get you there but which I have not loaded so cannot give specific input are: LilGun, Longshot, IMR Blue, and I think one of the Ramshot powders...enforcer?. Most of these will cover mid-power to near full power depending on how well suited your bullets are to higher velocities. There are others, but these are the ones that come to mind.

Random 8 said:

Unique is fully covered. I use it occasionally for .357 mid-power cast loads, but prefer HS-6 which is not on your list and a bit hard to find right now. Recently I've been playing with Power Pistol as I got some random lots at auction and want to use it up. Works very well in rifle-cast-158 loads. My 6" revolver hates it.

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When the supply comes back you might try Universal. It and Power Pistol are right next to Unique on the Burn Rate Chart. It's been good for me in the .357, and fantastic for midrange loads in the .41 Magnum.

Echo Unique for mid magnum, you'll need something slower for full power.

Unique, hands down!

My Ruger GP100 4.2" shot hits on steel at 90 yards. 6.5gr Win231 / HP-38, SNS 158gr RNFP coated,

Unique has always given the highest velocities with the lowest pressure. Yes, it's dirty. Who Cares? Is gun. Is dirty. If you find any 2400 it also works very efficiently.

derek45 said:

My Ruger GP100 4.2" shot hits on steel at 90 yards. 6.5gr Win231 / HP-38, SNS 158gr RNFP coated,

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HA! That range looks familiar! I'm also a Member of the ARPC! One of the guys lasered that plate you were hitting and it was 98 yards. You may be selling yourself a little short! I love taking my 6" security 6 out and nailing those furthest plates! Full house hardcast loads hit them with authority!

6.5 grains of Unique is a very nice load.

Did anyone mention Unique? It's about the only thing I use, or have ever used. It's dirty, but that's why they make Hoppes.

(Actually I found switching to plated bullets (Berry's), vs the commercial cast lead I was using took care of most of the crud.

GeoDudeFlorida said:

Where?

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It's out there. I bought a keg for 123 otd a couple weeks ago.
I'm glad it is because it's my preferred 357 powder.

Edit. I don't live in Florida though.

None of those powder listed will get you to Full 357 Mag levels. You will need a much slower powder to do that, 2400, W296/H110.

Use the slowest powder you have which is Unique. Should get you up to 75% of the mag level.

TG is the worst of the powders you listed. It's for light target loads. Runs hot which is not good for lead. And is very moody at the top end.