I was originally planning on buying the Glock Model 19 in 9mm for my wife and I to have as a backup or travel gun. We currently use a Ruger GP100 .357. at home because she feels comfortable shooting a revolver. However, since ammo is flying off the shelf and I can only find .40 and 45 should I: A. Stick with my plan and buy the Glock 19 in 9mm even though I can not find ammo. My reasoning behind buying a 9mm is if SHTF i figure the 9mm would be the most available since it is a NATO round. I am now starting to think that might not be the case since all I can find is 40 and 45. B. Buy the Glock 22 in 40 since I can find the ammo pretty easily. C. Buy the Ruger SR1911 in 45 since the ammo is easily available as well. Thanks in advance for your input.