Generally how fast should I need to push a 158 g jacketed hallow or soft point bullet to get it to expand? I have XTPs that I know are supposed to expand at 800-900 fps but some of the other 158 jacketed I have I don't know who the manufacturer is.

Given that, is there a powder and load in 357 that is somewhat efficient and economical, preferable low flash, that meters well that will get me that velocity........something under 10 grains? I would like to work up something in BE86 since it is supposed to be low flash and I have a lot of it but I also have Unique, HP38, HS-6, Accurate #5 and #7, Power Pistol, and Tight Group.

I haven't reloaded much 357, but a lot of 38 Special since it is more versatile. My standard 38 Special loads are as follows:

158g Cast or Cast HiTek coated over 4.0 g of HP38 which gives 715 fps

125g JHP over 5.3 g of HP38 which is a +P load which gives 920 fps

158g SWCHP FBI load of 7.0 g HS-6 with a Mag primer which is ArchAngleCD's load which is giving me 925 fps

I am super happy with these loads and they are all accurate and maybe my only compliant is that the 4.0 g load of HP38 feels too light sometimes......but I have a A LOT of 158 g JHP or JSP.

Back in the day when I started buying stuff from American Reloading I just bought whatever was the best deal. The result of that is that over time for 38 I've mostly loaded 125g JHP and ignored the 158 JHP and JSP since it was difficult to drive them fast enough in 38 Special. I recently did an inventory and I've got maybe 6 or 7 K of 158 g JHPs.

Some are XTPs, some are MFS, some I have no idea who the manufacturer is, and I even found 500 158g of Rainer copper plated hallow points which I guess I should sorta count as cast.

Any help, thoughts or advice is appreciated. I did do some searches on this but am suffering from info overload.

The only powder in your list that I've loaded for .357 jacketed bullets is Accurate #7. Hodgdon's website has data for #7 and a Nosler 158 JHP. I was using XTP's and found that the standard deviation got better as I approached the middle of their guidance....the starting load worked but had a high SD. I only tried 2 loads with #7 because I found that 2400 and #9 gave me more of what I was looking for. I eventually settled on 2400 as my go-to powder for .357.

All loads were with Winchester small pistol magnum primers and 158 grain Hornady XTP jacketed hollow points seated to an OAL of 1.585" using Federal cases.

9.5 grains #7
- 4" average velocity 971 fps, SD 42
- 6" average velocity 1168 fps, SD 28

10.0 grains #7
- 4" average velocity 1046 fps, SD 13
- 6" average velocity 1189 fps, SD 17

For comparison, 2400 gave me an extra 20 fps in both barrel lengths and the SD's were around 7.

As always, work up your loads in your gun. What worked safely in mine may not work for you.

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SWCA #3942 / SWHF #988

If I understand correctly you are wanting fairly low velocity and low flash 357 magnum loads using the listed bullets .
I would try either Ramshot Zip or Accurate #2 . Load data for both available on Hodgdons web site . Good Luck , regards Paul

If you want to shoot JHPs and want them to expand, check the unknown bullets at your loadings with jugs of water. Since expansion is the goal, just increase the load until you get the expansion you want in the water jugs.


For accuracy with heavy bullets I've found Acc #7 to be great. I never considered flash, though.

BTW: I made about 20 lbs of home make play-doh to shoot into to check expansion.

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"He was kinda funny lookin'"

Unique will do what you want.

I guess I don't understand the need for JHP or JSP bullets to expand at target velocities...?

Having not loaded with Tight Group or Power Pistol, all I can say is that ANY of the other five should work pretty well?

Cheers!

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Sit Reloader Sentiret

I haven't tried XTPs in decades, but back when, they weren't kidding when they labeled it extreme penetration. Expansion was unknown as I was never able to recover any.

OTOH, Sierra JHP/JHC do expand quite well, maybe not a much as the older Remington SJHP, but better penetration. Dunno about current production Remington. BUT that was for 125 gr. I'm not sure you're gonna get any 158 JHP to expand at .38 velocities. Rule of thumb used to be 1000 f/s minimum and maybe not then.

The lowest flash powder I'm aware of is BE86.

If you get a hankering to test the expansion of your loads and your range will let you, the milk jug system works well. Ballistic test medium

Just on hearsay I’d think BE86 would be worth a try. Power Pistol is not going to be low-flash, and my last 357 W231/HP38 load wasn’t either.

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Uvidíme se později, aligátore.

Well, if the lead bullets don't expand and work, there is always the chance

that the person might die later from lead poisinging !!

If you don't mind buying another pound of powder, 7.0-8.5 grains of Longshot does well for me out of 4" barreled revolvers. I find 7.5 grains to be the 'sweet spot.'