I believe I know the answer but my question is "Will my Glock 23 .40 mags work for the .357 Sig conversion?" Also, any advice concerning other parts that might need to be changed out to handle this round?

Thanks, GM

Yep.

Great! Thanks for the confirmations. Anyone else want to chime in on whether any replacement parts are recommended for the .357 Sig caliber?

Thks, GM

Barrel.

Ammo.

Magazines.

I'd mark the .357 mags with a silver sharpie in as a reminder to keep the mags with the correct barrel.

.40 mags work just fine with 357sig.

Yes they do. I have several 40S&W mags that I use in my Glock 31 Gen 4

Agree there, but what if you accidentally put a .357 loaded mag into your .40 gun?

Kinda like having a 9mm conversion barrel---accidentally putting a 9mm magazine in the .40 barrel.  It's been done before.

I suspect, like with shooting a 9mm through a .40 barrel, you'd get a pretty inaccurate shot.  

This. And .40 in the .357Sig?  No feed fully.

I guess people have done this junk and anything can happen, but that would require total lack of attention. In some kind of emergency/SD - why ever would you ever have a mismatch in that situation? Again - total lack of attention.

I only load up the magazines with whatever caliber I have the barrel in for.  If the .357 barrel is in the pistol, the .40 ammo stays in the locker.  I will only shoot one caliber or the other from my G23--never both--on a range trip.  I carry .357, but if I wanted to swap to .40 I'd unload everything, put the ammo back in the boxes, and reload with .40.

I started doing this because I was taking some friends out and had a friend try to chamber .40 in a 9.  So I started only bringing one caliber for each handgun type (he was not a regular shooter and had put a G23 magazine into a G19).  If I want to bring .40 and .357 to the range, I bring my sig set up one way and my glock the other, so that there is no confusion.