“the 10mm is essentially a .40 Magnum, relating to the .40SW the same way that the .357 Mag relates to the .38 SPL.”
I’ve seen what you are saying. All the so-called “nomenclature” on ammunition gets uncovered when you look at the actual dimensions. I understand that the .40 S&W is a 10mm Short. I was just responding to an earlier comment that the current batch of .40’s on the market are simply re-barreled 9mm’s. While I can get a 9mm (or a .357 Sig) barrel for my 229, it’s a larger frame than my wife’s Sig 239 9mm. There is no question, however, that the 9mm is a whole lot more comfortable to shoot. the .40 is very snappy.
Interesting. I would have expected SIG to use a different number designation for the different sized frame. SIG-Sauer nomenclature makes no sense to me. Is it purely arbitrary?