reloading light .357


December 6, 2012, 09:56 PM
If a light load was desired for practice, can a .357 case be loaded with .38 specs? Or do you simply use the lightest data for .357?

I know this is an ignorant question, but I've read people's comments about loading a "light .357", but I don't know what they specifically mean.


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December 6, 2012, 10:33 PM
Yes you can load a .357 with a mid range .38 load. You will end up with an even lower pressure and slower velocity than if you loaded that same amount in a .38 special case because you are starting with a larger volume. The consequences of a lower than expected load starts with the case not expanding enough to seal the gases and a sooty case. A lead bullet may cause leading in the barrel due to the bullet not expanding to the rifling.

With a very light load, the danger in using hollow points is having the jacket get stuck in the barrel. Finally with way too light a load, you could end up with a stuck bullet, but it is highly unlikely to happen if you simply used a mid range .38 special load in a .357 case.

December 6, 2012, 11:00 PM
I load .357 brass with anything from light (Not too light) .38 Spl loads, all the way to full power .357.

December 6, 2012, 11:10 PM
Ive thought of the same thing but have not experimented yet. I've been looking to work up some loads using Unique since it will fill the case without the possibility of a double charge. The current load data I have is from Speer #12 using a 158 gr semi-jacketed with a starting load of 6.9 - 7.7 gr and a small pistol primer with velocities of 978-1040 fps. And of course start low and work up watching for pressure signs. Or follow rsrocket's suggestions.

December 6, 2012, 11:57 PM
I don't have my datta or loading books but I have loaded light loads in a 357 useing eather HP-38 or Winchester 231 with a 158 grn SMWC or a RFP hard cast lead. Unique Trail Boss just to name some others.

December 7, 2012, 12:29 AM
I never shoot anything lower than start charges in the .357 and other magnums. If I want Special loads, I shoot them in Special revolvers excepting the .41 Magnum. Not that I'm into recoil because you'll never catch me shooting .460 or 500 S&W magnums and such. ;)

December 7, 2012, 12:34 AM
I found if you use the Max load data for a standard .38 Special in a .357 Magnum case you get a very light shooting round which is perfectly safe to shoot. I use mostly W231 for .38 special pressure loads in .357 Magnum brass and with a standard primer, not a magnum primer.

My favorite light plinking load for the .357 Magnum is 4.0gr W231 under a 158gr LSWC bullet. It's the same exact load I use for the .38 Special...

December 7, 2012, 02:25 AM
I like to stick with .357 data anytime I use .357 brass. There's plenty of data out there for light loads.

December 7, 2012, 02:30 AM
There is nothing at all wrong with using .38 Special load data in .357 Magnum brass. The other way around is a completely different matter...

December 7, 2012, 08:17 AM
Yes you can but is there a reason you don't just use 38 cases?

December 7, 2012, 09:00 AM
Some people only have .357 cases, although I use .38 cases as much as possible because they are much more plentiful and save the .357 cases for real .357 loads.

Sometimes, there is a hard ring that is left in the cylinder after shooting a bunch of .38's in a .357 gun. That makes using .357 cases tough/impossible to insert. Cleaning the residue ring at home is not a problem, but it is a bit of a hassle at the range.

December 7, 2012, 09:28 AM
Hodgdon data lists 3.4 gr W231 as starting load for 158 LSWC in 357 magnum.

December 7, 2012, 09:38 AM
...I use .38 cases as much as possible because they are much more plentiful and save the .357 cases for real .357 loads.

+1. Lots of .38 cases around and they cost about a 1/3 of what .357 brass does.


December 7, 2012, 10:30 AM
Ran some numbers in Quickload for a light .38 load in a .357 case awhile back and the drop in pressure as well as the drop in velocity were on the order of negligible.

December 7, 2012, 11:21 AM
I will load lead bullets in magnum cases at 38spl pressures, using powders suitable for 38spl.
I will load plated bullets at pressures between 38spl+p and .357 mag. starting loads for jacketed bullets, again using powders suitable for 38spl.

December 7, 2012, 02:35 PM
Thanks for all your answers!

kingmt: because I wasn't thinking! I originally wanted to have only .357 brass on hand. But I have shot a box of .38 through it, so I do have .38 brass. Feel like an idiot now!

December 7, 2012, 09:42 PM
I think once a handloader settles down & really understands what is going on we rarely load to max for general shooting.

Hunting or pure target we seek loads that work & sometimes it`s a balance/compromise to get satisfactory results.

December 7, 2012, 11:03 PM
I believe there is a lot of truth to that.

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