[Rich Jenkins]

I understand that the 17 is the same profile as the 15. But that’s just one more way to get cross with an overzealous LEO. Seems like SIg kinda threw us in Illinois under the bus, relegating us the 12 rounds to remaking legal.

So I’m asking what are the prospects of a 15 rounder being offered by a third party mag producer, perhaps mecgar or pro mag etc. ?

Welcome to Sig Talk.

I think the likelihood of a 15 round magazine vs. say the current 17 round Macro is virtually nil.

This is for the reasons you stated; the 15 round mag is for all intents and purposes (save one) the same physical envelope as the 17, and as they say, unless you are drowning or on fire, who doesn't want more ammo. (Pro Mag magazines I hear nothing good from, Mec-Gar are at the other end of the spectrum. All the MG mags I've owned have been very high quality.) (*the one exception being state-specific laws, which restrict magazine capacity to arbitrary limits).

One hope I have is that Sig (or Mec-Gar, or Check mate) will introduce a flush-fitting Macro mag. Downloading by 2 and redesigning the tube and basepad to be flush would help with Macro concealment, I reckon. It would remove the ability to strip a mag by using the basepad as a handle, of course, which is my guess why a flush 15 is not a thing.

Otherwise, keep an eye out in the classifieds, they pop up from time to time. Again, welcome aboard.