I forgot to say that NONE of my firearms are Unfired, and i have never had a jam in any of my workhorses. 5-7mags minimum. I also modified my Beretta M9/92FS 9mm mags(since they are so plentiful) to work in my SigSauer P226 9mm. I just relocated the notch for the magazine catch on the mag. And I can use them on either pistol. And without modification, I have loaded .40 into the 9mm P226 mags and shot them in the SigSauer P228 and P229 .40cal models.
Hope that helps people that can't find certain mags!