The world is full of people agonizing over the ultimate caliber, the ultimate make and model of bullet, etc. And in the service ammunition world, there's a lot of market share money at stake if you can put a round in the hands of police departments and real world performance shows better terminal results, better terminal results out of short barreled service pistols, less recoil for the same terminal ballistics, etc.
That goes on even within companies: Winchester and others offer different bullet designs of the same weight in their service lines i.e. bonded jacket designs versus skivved jacket bullet designs. Speer offers law enforcement their Gold Dot versus their Gold Dot 2 versus their Gold Dot Short Barrel for example: same weights and virtually the same velocities. Winchester does similar development and marketing, offering jacketed hollow point, bonded, bonded hollow point, and their T-series; four different models/designs of the same bullet weight in police service ammunition for that caliber.
Now add that all (or maybe nearly all, I don't follow what's happening in the market) the companies then offer a +P version versus the standard velocity version. Winchester says "hold my coffee and doughnut and watch this shyte" and goes them one better by offering 9mm agencies standard velocity, +P, and +P+. There is no SAAMI standard for +P+, by the way. Or wasn't several years ago. They can't do that with 40 S&W because there is no +P standard for 40 S&W: my guess is because the original 40 S&W was designed to fit into existing makes and models of pistols that were engineered to operate with the 9mm - a lot less metal in those firearms when you have to remove some in some areas to take a double stacked .40 S&W instead. I could be wrong on that, but the 40 S&W didn't have to deal with a pressure envelope developed at the turn of the last century like the 9mm and 45 ACP. Ditto the .357 SIG, a merely necked down 40 S&W for the true believers in high velocity.
If that seems like over-kill (and it does to me from an individual standpoint), consider that there are individual cities in the US with 30,000 - 40,000 city police officers. While there is also the county sheriff's office overlaid over that, the state police, the federal alphabet agencies, etc. When they select a caliber, a model of pistol, and a brand and model of ammunition to go with it, there's a lot of testing that goes on, most of it based on the FBI's testing standards with probably a little local extra thrown in, and maybe favouring one LEO shooting scenario over another.
A friend I met in the military while he was serving in the Rangers left there to join the Wyoming Highway Patrol and was shortly also one of their firearms trainers (advancement comes quickly in Wyoming where there aren't many of them and a lot of places can only be described as 'dreary'). He said they decided to choose the 40 S&W 180 grain flavour (can't remember if he told me make and model) because their major concern was a bullet that could best get through automobile metal and glass and still be able to perform effectively on their assailant. They are only law enforcement when it comes to criminal acts involving a motor vehicle; 99% of their work has to do with traffic safety and traffic/transportation ticketing. Which means almost all of their shootings involve vehicles - Scott said he and a lot of other guys had their patrol carbine right in the front seat where they could grab it instead of their sidearm if the fight started while they were still in their PC. So they really don't care whether their round of choice does well dealing with drywall and heavy winter clothing as much as they care if it's constructed so it can go through auto metal and glass and still perform effectively after it's done that.
Anyways... with all that in mind, trying to win the contracts in all those markets and the value of those markets, you should be able to imagine the R&D that goes on as those companies compete between themselves, and how they allot their R&D time and money between calibers, based on what share each caliber has within the law enforcement world.
If you want to amuse yourself picking fly poo out of pepper, you can visit Vista's website: they're the parent company of Federal and Speer and have a website for their law enforcement lines of ammunition. They may have one as well for the personal defense stuff you can buy off the shelves, I don't know. Anyways, here's their website for comparing calibers, weights, designs, etc for Federal and Speer:
http://www.le.vistaoutdoor.com/ammunition/default.aspx
One thing you may or may not notice is the narrow velocity window that they all fall into. Now, if the boutique brands like Double Tap, Underwood, etc can take those same bullets (or cloned backwards designed bullets) load them far hotter to add about a 100 fps or more, and then sell them for far more money than Speer, Federal, Winchester do, you have to wonder why those companies aren't running their duty ammunition the same/similar bullets at the same velocity? Mo' velocity equals mo' performance, right? Just like mo' diameter equals mo' performance, right?
I don't follow the service ammunition world all that closely, but I have yet to hear of a police agency that decided that the best service ammunition they could provide their police officers was from one of the high velocity boutique brands. I'm pretty sure a lot of the reason has to do with those bullets don't do as well at those velocities when subjected to the same testing criteria as all service ammunition does for acceptance. A couple of the main manufacturers ballisticians have said numerous times that, when you load their bullets above the velocity envelope they were designed to properly perform in, what you get as a result is just a crap shoot. Not unlike when the early magnums came out and the cup and core hunting bullets of the day that worked fine in the 30/06 and similar calibers failed when driven hundreds of fps faster.
On the other hand, those boutique brands offering WFN hard lead bullets for using in a handgun intended for hunting or as a bear wrench are a pretty good choice: the majority opinion is still that a hard WFN lead bullet is about as good as it gets for critter defense and hunting, except perhaps for small light animals like whitetails. Handgun velocities can't screw up a hard WFN lead bullet, even if you can manage to add an extra 100 fps or more.
Anyways, to me it's pretty obvious that there's a whole lot of interrelated factors in choosing ammunition, whether it's an enforcement agency with hundreds or perhaps tens of thousands of officers, or whether you're picking ammunition for hunting or to use as the camp bear wrench. Plinking is the easiest: how cheap and accurate enough?
You could solve your ammo access problems by investing in some low cost reloading equipment, of course...
