.357 Sig Case Resizing

I'm wondering if anyone else has notice this (not that there's many of us reloading .357 Sig).

New Starling brass appears to have the case shoulder closer to the head (therefore farther from the mouth) than my case gauge suggests it should be. This means more neck, and the possibility for more next tension. They still chamber and fire just fine like this. Likely because the case with seat of either the mouth or the shoulder, based on which one hits first in the chamber.

When I resize fired brass, I set the shoulder so the case fits the go/no-go case gauge, but between the powder residue coating the inside of the neck (despite tumbling it's never like new), residual case lube, and the reduced neck length, I tend to see prefired cases are more likely to suffer bullet setback.

I'm wondering if maybe resizing the shoulder farther towards the case head is a better way to go. However, I realize this may cause the case to wear more quickly at the shoulder. Any thought or experience with this?

JPIMBO said:

Very interesting thought about the powder residue in the neck even on my 40. Always so tight after bullet seating.

Click to expand...

Actually, what I've noticed with the residue on prefired cases (including .357, .41, and. 44 mag) is that bullets seat just a little easier than with new brass. In fact, I had some coated lead bullets that I loaded into new brass, and saw the coating breaking off from friction even with a good flare to the mouth. No such issue with prefired though. It's been my experience that the residue makes the inside of the case slightly slick.

JPIMBO said:

Sizing my bullets is one thing but I think that extra thickness may contribute to the carts to be a little too big for the gauge sometimes. But your right the residue is a smooth lube plus the stretch of the case mouth helps a little. They don’t anneal new pistol brass. Do you size your coated bullets after coating?

Click to expand...

I don't cast my own. I just buy from SNS, MBC, or similar places.

vaalpens said:

It does not seem SAAMI gives much wiggle room from the head to the shoulder. What are the measurements?
View attachment 953931

Click to expand...

Somewhat hard to accurately measure, though it seems to be fairly close. However, here are some pics of a resized case with my case gauge.


And here are the same shots with a piece of new brass.



Comparing the two directly, things don't look very different. But the gauge tells a slightly different story.

I decided to adjust my resizing die. It's bottomed out now and reads between the two. Perhaps that will work a little better, but it should work at least as well as how I've been resizing up until now.

packetloss said:

I've never had an issue with lube or residue on .357sig cases. If you aren't wet tumbling you should.

Click to expand...

I'm dry tumbling, and probably won't be changing that any time soon. Unfortunately. But that is likely part of the issue.

Just to be clear, when I was talking about coated bullets, that was for the magnum cartridges. With .357 Sig I only use copper jacketed (or just recently, solid copper).

packetloss said:

Just make sure to tumble them outside and you should wear a P100 rated mask when dealing with the media or putting cases in it or taking them out.

Click to expand...

Interesting. I don't remember hearing much about that until now. But perhaps I should look into wet tumbling.

cfullgraf said:

Dry tumble cases with the lid in the tumbler. Use a bit of a liquid car polish like Nu Finish which will bind up the dust and the dust will not be an issue.

Don’t get crazy with the polish as it will load up the media such that it won’t work and leave black tar like smudges on your cases.

Importantly, do wash your hands after handling cases out of the mefia.

Run the tumbler out doors and use PPEs if you fell more comfortable.

Click to expand...

I certainly had been washing my hands. After every aspect of reloading.

The lid on my tumbler has slots in it. So on my way home I bought a big plastic tote (with lid) to put the whole tumbler inside.

I'm also going to stop using the center hub of the tumbler to vibrate media out of the cases as I pull them out. I'd been doing this since I began reloading a few years ago - lightly holding each case upside down whilst pressed to the hub - and obviously the tumbler has to be on for the vibrations to help, which means dust. I'll do it differently from now on, and I'll get some car polish too.

Thanks to everyone looking out for my health.