Weapons Man wrote a seminal article on why SOF forces have almost universally transitioned to the Glock 19 (with one exception who may still be shooting .40S&W) as their go to war hand gun. I agree with everything he says. However I do have some potentially redundant thoughts of my own. The Glock 19 is obviously a Glock. For the uninitiated it is on their ‘compact’ frame and chambered in 9mm. We will briefly talk about each of those characteristics. Glock pistols: -Reliable. They are pretty much the gold standard in reliability for handguns. They perform well under adverse conditions with minimal maintenance. You might argue a SWAT Blaster 900 is equally reliable but finding one that is more reliable is going to be difficult at this time. -Repairable. They can be repaired by a non expert with a single punch and true drop in parts. -Long life. These guns can put a whole lot of rounds down range without serious damage. (particularly in 9mm, .40S&W Glocks actually have some issues here.) -Price. They are very affordable pistols. -Ease of use. Easy guns to learn and shoot well. -Commonality. If people make a holster they make it for Glocks, ditto sights, etc all. If a store sells gun stuff they have Glock stuff. Compact size: -About the largest size handgun a normal sized person can conceal with minimal hassle. I didn’t say no hassle. Personally I think people who believe they are concealing a Glock 19 under a normal sized t shirt are probably unaware or being dishonest with their selves. Maybe they can from one angle standing still but moving and doing normal life tasks not so much. To actually hide the gun a pair of pants that will allow the gun to be carried IWB and a larger shirt are going to be needed. -Best all-around option. If you want to balance shooting (either recreationally or for defense) and concealed carry this is probably the sweet spot for most people. So if a person was going to have one handgun with them to do a couple different things this size is the way to go. 9mm: -It works. With modern defensive ammunition the difference between any of the common defensive calibers (9mm, .40S&W, .45acp) is mental masturbation. Sorry folks, I really don’t care what Jeff Cooper said 30 or 40 years ago, it is true. -More bullets. It will probably give you 2 more bullets than .40S&W and 3+ more than .45acp in the same sized gun. More bullets is better. -More controllability. Better for smaller and weaker people. Also this means faster follow up shots for everyone. -Commonality. If a place sells bullets they will have 9mm. Compared to the other 2 options it’s at least slightly more common. This is more important for international types as .40S&W and .45acp are not going to be common elsewhere. Note: The primary difference between the Glock and the various competitors (S&W, Ruger, etc) in favor of Glock is going to be reliability and commonality. You might not be able to get mags/ parts/ accessories for a Ruger SR9 or those new FN pistols but the gun shop will have Glock mags.