SPEER .357 Sig headstamp "S" suffix, what does it

I have a standard enough looking nickel plated .357 Sig case headstamped “SPEER 357 SIG S”. What is the purpose of the smaller “S” at the end of the “357 SIG” part of the headstamp? It looks out of place as it is slightly smaller, and is offset in relation to the rest of the stamp. Any help would be appreciated.

Someone must know this, I presume it is something simple.

The “S” on this headstamp simply signifies a smaller than normal flash hole. Evidently, Speer found that reducing the diameter of the flash hole gave better results with some of the powders they use in this catridge. They may have felt it necessary to mark these cases so that reloaders wouldn’t stick decapping pins in the flash holes - I have never reloaded this caliber but assume a normal decapping pin is probably too large in diameter for these cases. Maybe that’s a wrong assumption, since I don’t recall seeing any public notice, on boxes or otherwise, of the significance of the “S.”

Thanks, I knew there would be a simple explanation for it. The flash hole is slightly smaller than that on another .357 Sig case I have.

Gee thanks guys, now I have to look through the eleven billion .357 Sig cases I tossed into the scrap bucket to see if I have any with the “s” headstamp!


AKMS, if you don’t find one, I’m sure I have many (already reloaded, though). They decapped fine, but, IIRC, the primer pockets tended to be on the large side (noticeably less resistance in seating the new primer) so I colored the bases to mark them for discarding (no further reloads) when the present load was fired. I was unimpressed and - apparently incorrectly - presumed the “S” marked them as “secondary quality” or some such. It could be they had been reloaded before (didn’t appear to have been) and firing or something in the reloading process enlarged the pockets (which happens after some number of reloads on most casings if they don’t show other defects first).