.357 question

[TimSr]

So-again, my issue is with shorter cartridges not reliably cycling through the rifle.

Then I guess I'm not understanding your question.

Using the same mixture in a .357 case instead of a .38 Special length case, does anyone foresee any problems?

This was the question you asked in your orginal post that people have been answering. The most common answer was "yes".


If your question was whether a 357 case will end your cycling issues, the most common answer was also "yes".

[Wishoot]

One of the best pieces of advise I came across for reloading my Winchester 94 was to load up a few dummy rounds and use them to verify smooth cycling before you spend the time priming and charging the case.

[Unclenick]

Originally Posted by TimSr

If he goes to a larger case, he will be CHANGING his load, and it may not continue to fire as it did before.

Yes, but he's talking about a low pressure load of a fast powder. It's going to burn fairly completely in the long barrel, which means it will make about the same total amount of gas which means the muzzle pressures will be about the same. So if the bullet didn't get stuck in the bore in one due to failure of the pressure to overcome bore friction, it's not going to happen in the other.

The peak pressures would differ by 20% if you assumed the .357's brass has the same capacity below a bullet base as .38 Special does when the bullet is the same distance forward of the head. But Starline tells me the .357's taper is normally longer, so that if you seat a bullet the same distance from the head in both, the .38 Special will have a little more capacity. That means the powder space doesn't increase quite as much going from .38 Special to .357 Magnum brass and using the same bullet seating depth (from the case mouth), as it would merely seating out 0.135" further in a .38 Special case.

Using QuickLOAD's default case capacities and assuming a 20" barrel, going from 1.455" COL in .38 Special case to 1.590" in a .357 magnum case with a 125 Grain bullet over 4.0 grains of Unique, I get an 11% drop in peak pressure from about 8300 psi to about 7500 psi, and a 3.6% drop in muzzle velocity from 1091 fps to 1065 fps and a slight 2.6% drop in muzzle pressure from 723 psi to 704 psi. velocity from a 20" barrel for the load described in the OP when moved to a .357 case. It shows a small percent powder not burned, so the muzzle pressures differ by that 19 psi in the simulation. I doubt that will play out in the real world exactly. But either way, the differences all would be overlapped by the range of shot-to-shot variances you'd expect from either load by itself.

So while performance is not identical, neither do I see it being a major factor in this situation. I, personally, would go to something a little faster burning to get a little bit higher peak pressure. The case seal against the chamber will then be a little better assured, and the velocities will be closer together.