low power .357 loads

[Hair Trigger]

I'm looking to load some .357 cases to something on the order of a .38 +P. I have a bunch of 125 grain JHP Hornady XTP's that I'd like to use, but would rather not load them to even the low end of magnum range, in order to preserve my forcing cone, etc.

Anybody got a powder and amount they'd like to share in that sort of load? If so, do you still use magnum primers with it, or standard primers, and what kind of velocity are you getting? I'd like to get around 950-1000 fps max. Something that will meet the power formula for IDPA.

 

[rwsmith]

You can use.....

You can use any primer/powder/bullet combo for 38+P loaded in .357 cases so the list is long.

I've made these loads with Unique, Bullseye. Tightgroup should work about like BE. Most any fast to medium burning powder should do the job easily. The slower powders generally don't burn as well with reduced loads.

I've used 140 grain JHP and 158 gr SWCs.

I always use standard primers with these powders. I'm starting to use some Magnum primers but I drop the powder back .2 grain.

 

[BC38]

FWIW, when I load 38 specials in 357 cases, I use a regular primer - just as I would with a 38 special case. I also load them at the high end of the range for 38's - that's still much milder than magnum loads.

 

[Willyboy]

Moderate 357 loads

I use 5.0 gr of HP38, which is a little over +p loads for that powder. But in my 6" model 27-2 it is moderate recoil and very accurate.
Willyboy

 

[Willyboy]

Mod 357 load

Whoops; the bullet is 158gr SWC for 5.0 gr of HP38. Willyboy

 

[BC38]

I use 5.0 gr of HP38, which is a little over +p loads for that powder. But in my 6" model 27-2 it is moderate recoil and very accurate.
Willyboy

LOL, in a 6" n-frame like your 27-2 the hottest Buffalo Bore 357 rounds should only produce "moderate recoil"

 

[rwsmith]

You get Corbon or Buffalo Bore......

FWIW, when I load 38 specials in 357 cases, I use a regular primer - just as I would with a 38 special case. I also load them at the high end of the range for 38's - that's still much milder than magnum loads.

You get REAL +P stuff much cheaper when loading in the interface between .38+P and .357 magnum

 

[johngalt]

Use .38 special data.

 

[muddocktor]

I've been playing with Longshot lately in several calibers, as I had bought an 8 lb jug of it back when it was impossible to find powder a bit over a year ago. And I have been liking my results with it in 44 Mag, 357 Mag and 9 MM. I haven't tried it with 125 grain bullets but have run it quite a bit lately with 158 grain coated SWC. I've found that 6.8 grains Longshot with the 158 grain SWC coated give my 975-1000 fps out of my 6 1/2" 27-5. And looking at the Hodgden data, they have a 38 +P load shown for the 125 grain XTP at 7.0 grains. I think you would find that would be a nice load to try, if you have some Longshot powder already.

 

[Rule3]

Without knowing the velocity it is unknown if it meets your power factor but loading 38+P data in a 357 mag case is no longer a 38+P, it is pretty much just a 38 special. Most +P loads are just the max 38 special load

Use the start load of 357mag loads with a medium powder like HP38 or such

 

[Nevada Ed]

+1 with the guys above;

The problem with the 357 magnum is............
it IS a MAGNUM.

My minimum full load with a ball powder was 1230 fps out of a 6" barrel. I never tried for a "SLOW" 125gr load in all my years of loading the magnum.

With a 38 special case in the 6" I was able to get from 888 fps up to 1210 fps, which should meet your needs some where along the road.

Find some data that you like and dump it in the long 357 case and see what happens.

Lots of data out there..........
good luck.

 

[Hair Trigger]

Thanks, guys, for the good info. I generally use Hornady's load data for everything I reload, and sometimes cross-check with Sierra or Barnes or one of the powder mfg's data. There's a sizeable gap between the top of the .38 Spl and the bottom of the .357 in terms of amount of powder for a given MV, and the powders used in the .357 are generally a little slower than for the .38.

I wondered how the faster powder, such as Accurate #5 would behave at .38 amounts in the slightly larger .357 case. I imagine pressures would be a bit lower than the equivalent load in the smaller case.

I think I'm going to start with the lightest .357 loads and work backwards a little, and maybe try some .38 powders in the upper 1/3 of published .38 loads, in the .357 case.

 

[Rule3]

If the powder you use is not H110 or 296 you can develop loads by adding 10% for the increase case size of a 357 to the 38 special load data,

Still start at the low end and work up, You effectively would develop your own 38 +P or even +P+

Faster powders will increase the pressure fast and more. Try medium burn like HP 38 or Unique.

 

[peh_7]

Try Trail Boss

I'm not sure what you are really trying to get but you should check out loads using "Trail Boss" min to max loads produce 874 to 1035 fps with a 125gr lead (or plated) bullet as per the Hodgdon data.

peh_7

 

[Nevada Ed]

Uh;
about trying Trail Boss.............

Good luck finding it.
I'm going on three years.

 

[peh_7]

Sorry to hear that it's not available in NV. It's be on the shelf on an off for the last 18 Months here in MI. Although I did check and noticed that currently it's not in stock at any of the mail order suppliers???

Good luck

 

[rwsmith]

That's not all..

Faster powders will increase the pressure fast and more. Try medium burn like HP 38 or Unique.

Faster powders can also increase the size of your cylinder and barrel if you overdo it.

 

[ArchAngelCD]

If it were me, I would check your manual and find a .38 Special +P load I have powder for and load the max charge in a .357 Magnum case. Check it over a chronograph and if your happy with the accuracy and velocity you are done. If not play with it a bit till you are happy. It's not as complicated as you might think.

 

[STORMINORMAN]

Often wonder where this myth of "normal" factory 125GR 357 Magnum loads destroying a K-Frame forcing cone ever came from?

Anything made by man can be broken but there is a world of difference between a steady diet of 110GR SuperVels and/or Elmer Keith-style 38/44 loads in an Airweight LadySmith and factory ammo in an all steel K-frame...

 

[oddshooter]

You are right in that Today's "normal" factory 125GR 357 Magnum loads don't do it.

That myth was formed when the original 357mag was rated at 1500 fps. You don't see those now except in specialty loads now. I chrono lots of 357s at under 1000fps today. Some cop shops ran 10s of thousands of those hot loads thru their K frames. The crack developed on the forcing cone where it had been cut down to allow the cylinder to close.
Many have documented this issue.