There has been a lot of research and write ups about 9's and 40's. Most law agency's have or are in the process going back to 9mm. It's a very true flying projectile with good penetration.
Yep. I did a couple classes with Larry Vickers and he used to talk about bigger is ok but accuracy is final. Most people shoot better with a 9 due to the lower recoil and that's what is important. Think the original quote is from Wyatt Earp - "Speed is fine but accuracy is final".
I like having the option of the calibers as well, like what you are saying with the scare of a shortage. When i first starting into guns when old enough, i thought i needed one of everything and still have most of it today. 1911 in .45, s&w mp in .40, and a few 9mms, lotsa .22 and .223, 12ga, even 7.62x39 ak stuff, just to have everything covered "in case" ... now its all just adding glass, sights, triggers, spare mags, rigs for each, like nutnfancy says, being "tactically squared away". Now that the business is going well I can get a little more specific, like the special loads, and I love the 10mm stuff as well. Ive got a Glock 20 with a TLR1 that i carry some in the winter and everytime im camping or hiking, bear gun, hog, sasquatch, whatever really, the G20 is 15rnds of nothing is gonna live through that.