TruthTellers
New member
That's what I said earlier. Start with 9mm start loads and see what results OP gets.your additional comments have given me a better idea of what you intend to do.
Thanks for explaining further.
You want approx. 9mm level loads in brass that fits in your gun.
Ok, in general terms a pressure vessel is a pressure vessel
Your brass has slightly more capacity than 9mm Luger..ok, fine, you can work with that. A quick look at an old book shows several powders pushing 9mm 147gr (the closest the data gets to 158gr) showing max loads with somewhere between 4 and 6gr of powder.
you have plenty of room for that.
The loads I looked at topped out in the 950-1050fps range, but that's from a semi with a 4" you'll probably get a different result from a revolver, what's your .357's barrel length?
Another thing to watch for is accuracy / bullet jump. May not make a noticeable difference, or you might be shooting patterns instead of groups.
No way to know until you begin testing. you might find some bullets make a big deal of how much they have to jump, and others behave differently.
Cross that bridge when you come to it.
If I were doing it, I'd start with bottom end 9mm load, load a few, and see how they behaved. Chrono them for speed, and consistency. Once you know what you've got, work up carefully like any other load.
The accuracy and bullet jump I have no insight into, my focus was solely on velocities and pressures with .38 Short. Accuracy is probably not going to be as good as .38 Special.