powder charge relative to case capacity: a factor?

[bottlerocket]

This will be a specific example, but I'm looking for some insight as to how it affects q broad range of cartridges. I was looking at my brass collection and noticed a significant lack of 357mag with a noted surplus in 38spl. Now i know loading 38spl there is TONS of real estate for powder, even on the snappiest of loads, same for 357mag. But from everything I can tell the brass is identical except length.

So my question is what is the effect of loading a 357mag powder charge in a 38spl? Obviously there is the safety issue of accidentally loading one of the magnum rounds in a 38spl gun. I only own 357mag revolvers so that risk is mitigated by the fact that only my guns shoot my reloads. Beyond that issue, does the function of case volume vs powder charge play any role in the performance of the round? Sorry if its an ignorant question, I just do not recall ever reading or seeing anything on the subject.

[YALE]

The short answer is yes.

[svauto-erotic855]

Entire books have been written about internal ballistics. Case volume plays a HUGE role in the necessary powder charge.

You can over charge .38spl cases if you are using a .357 frame revolver but you will be working outside of published load data and taking your health into your hands. Your eyes don't grow back. Don't be a cheap fucker and buy some .357 cases to be safe.

[CJ]

You can equalize case pressure by setting the bullet further out. However I believe even at the same case pressure a .38 SPL case may fail. I believe a .357 has a thicker webbing.

[Nash B.]

I believe a .357 has a thicker webbing.

I know that's true for 10mm vs .40 S&W

[dee]

I've seen it done with no I'll effects but I don't feel it's a safe practice.

[Bassics]

there are quite a few loads for larger bullets that are designed to be used on a 38spl case, especially 180gr. The reason for doing it is to shoot a 357 maximum bullet from a normal 357 mag chamber, although not anywhere near the same pressures.

If you try and load the longer bullets in a regular 357 mag case you have to seat them far too deeply. Case necks on straightwalls are tapered inside. Cutting the 357 case back doesn't address this well enough.