Which 357 Magnum powder?

[trulyapostolic]

Which powder will give the highest velocities out of a 3" barreled 357 magnum revolver? I'm loading 158gr. JSP bullets and have already had no luck with VV N110. Should I look for something faster or slower (burn rate)? I'd like to get the 158's over 1200 fps out of this gun. Thanks.

 

[Dragon88]

H110/W296 will likely get you the highest velocity, but at the expense of extreme report and flash from your 3" barrel. Try 2400.

 

[ArchAngelCD]

Any load that produces the highest velocities in a 6" barrel will also produce the highest velocities in a 3" barrel. Of course you won't get the same velocity from a 3" barrel that you will from a 6" barrel but the statement holds true.

IMO the highest velocities in a .357 Magnum with a 158gr bullet will be generated by W296/H110. With a heavier bullet Lil'Gun will be tops. Of course 2400, AA9 and 4227 will also do a good job.

 

[Ursoboostd]

I've been loading 13.9gr of 2400 with lots of flash out of a 4" barrel.

 

[trulyapostolic]

Thanks fellas, I'll pickup some H110. I've got some HS7 that I was going to try too. VV N110 gives great velocity and accuracy out of my 44 so I was hoping the same from the littler bore.

 

[lazy]

I loaded some .357 and got an average of 1145.60 with 14 grains of 2400 out of a 4" 686. 158 gn rnfp bear creek bullet molly coated.

Same load with 158 gn Hornady JHP, XTP average fps 1017.50
gun to chronograph was 20 feet.

 

[fredj338]

Thanks fellas, I'll pickup some H110. I've got some HS7 that I was going to try too. VV N110 gives great velocity and accuracy out of my 44 so I was hoping the same from the littler bore.

It should. As noted, highest vel will always be with the slowest powders, regardless of bbl length. You will pay for it though in blast & flash. A powder like Unique will have slightly less vel, maybe 50fps, but a lot less blast & flash.

 

[tops]

158 gr. SWC, 15 grs. 2400. 2 1/2 in. 1246 fps., 4 in. 1306 fps., 6 in. 1429 fps. Larry

 

[ArchAngelCD]

Thanks fellas, I'll pickup some H110. I've got some HS7 that I was going to try too. VV N110 gives great velocity and accuracy out of my 44 so I was hoping the same from the littler bore.

Just be aware, you should not try to download H110 much at all. It does not react well to lower pressures so it should only be used for top end loads. Also, I highly recommend using a magnum primer with H110/W296. Some reloaders will tell you it's not necessary but believe me, you will get a much better ignition and more consistent ammo thus better accuracy with a magnum primer.

It should. As noted, highest vel will always be with the slowest powders, regardless of bbl length. You will pay for it though in blast & flash. A powder like Unique will have slightly less vel, maybe 50fps, but a lot less blast & flash.

I have to disagree with the potential velocity between Unique and H110. There is no safe way to generate equal or close to equal velocities with those two powders, Unique is just too fast a powder in comparison. Hodgdon lists a top velocity using H110/W296 of 1966 fps with a 125gr bullet from a 10" test barrel. Alliant lists a top velocity of 1343 fps using Unique while fired from the same length 10" test barrel. Even if the numbers are a little off I can't see safely making up over 600 fps.

 

[Joni_Lynn]

The powders I'd use would be WW296/H110 followed by AA9 and 7 and then Unique. There's probably others but I look no further than that group.

 

[Dragon88]

The powders I'd use would be WW296/H110 followed by AA9 and 7 and then Unique. There's probably others but I look no further than that group.

Very true. If you can't do it with 357 Magnum and one of those powders, then it probably doesn't need to be done all that much.

 

[trulyapostolic]

Well, I'm impatient. I went and purchased some H110 today, loaded some rounds and fired them tonight. Tried 16.0 and 16.5 gr. H110, Win magnum primer, and Speer 158 JSP bullets. 16.0 gr. averaged 925 fps, 16.5 gr. averaged 1000 fps. Both loads were extremely mild to shoot and showed no pressure signs, cases practically fell out and primers had nice round edges. Think I'll bump her up some more until we start to see something. I'm shooting this out of my 19-7 PC revolver and want a full power load to see how effective the compensator works at those levels. I don't expect to see much over 1200 fps max out of the 2 1/2" barrel, but we'll see. I appreciate the advice.

 

[trulyapostolic]

As a side note 12.4 gr. of HS7 averaged 1042 fps. My chrono was 15-20 ft. from the muzzle. That load shot real well, we may play with that powder some more also.

 

[Dragon88]

You've only got .2 gr more to go before you bump into the manufacturer's published max. Be careful and consult Hodgdon's online reloading center.

http://data.hodgdon.com/main_menu.asp

Don't get so wrapped around velocity that you ignore pressure. 200 fps isn't worth it.

 

[ArchAngelCD]

Are you applying a firm crimp? A slow powder like H110 needs the additional crimp to have the time to build pressure and you might just see a little extra velocity too.

 

[Skip Sackett]

H110 is a great powder for the carbine too. I have recently switched to Lil' Gun though and use a Brian Pearce load that develops 2100fps from the wife's Marlin 1894 with a 158gr bullet.

 

[Wheelgunner840]

Like Joni_Lynn, I use AA#7 and AA#9. I am getting 1250 fps out of a 4" bbl with 158gr. HDY HP-XTPs.

WG840

 

[alwslate]

I don't think you're going to see 1200 fps out of your short barrel with
158 gr JSP bullets at acceptable pressure levels. If you really want 1200 fps try a 158 gr hard cast bullet.