The criminals put up such a fight because one of them had a mini-14 and knew how to use it. Against that, any short gun is going to be outgunned.
It wouldn't have mattered as much if he and the other idiot had been gunned down sooner by the agents, who outnumbered them 4-to-1. Early in the fight, one bullet stopped about an inch short of punching a hole in one of their black hearts, and about half the agents present suffered from capacity issues with their revolvers.
While one could argue that this short penetration issue was just a bit of bad luck, the fact is that the 9mm load they used at the time could not fully penetrate a human-sized target from every angle. If they had a pistol round that could, then at least they've covered a whole class of potential failures to stop. Shot placement would still be the main determining factor, of course, but the question of adequate penetration is something that can essentially be made a non-factor ahead of time.
They really should have started arming their agents with long guns, but instead they spent a bunch of money designing a cartridge they couldn't use.
10mm Auto was already around in 1983, three years before the shootout. They wanted to get as much of a margin as they could while keeping capacity high. Unfortunately, it didn't quite work out.
After the shootout, the FBI decided that more capacity is useful to have, and .40 S&W (and 10mm, for that matter) offers more capacity than .45 ACP and a performance edge over 9mm that together give FBI agents greater confidence in their service pistols.
I'm going into a business administrations degree; part of my teachings is about cost and profits.
Developing new calibers is what firearm and ammunition manufacturers invest in all the time to help boost sales. That's why there are so many largely redundant calibers out there--if a caliber becomes successful in the market for whatever reason, then many people will want to buy another gun chambered in that caliber and additional ammo to go along with it. They didn't teach you that in school?
Simply put, and at the at the moment, the costs of coming up with a whole new cartridge that wouldn't require gun manufacturers to augment their current 9mm lineup is still just too much then to just consider using the .45 acp.
They could have done that, although 9mm also had the potential to achieve the increased penetration they desired, albeit with a smaller diameter bullet. But what they wanted was the best performing caliber available, which was 10mm, and only later did they realize or decide for some reason that it not entirely feasible. Smith & Wesson and Winchester, fearing that they would lose the additional sales that would accompany the use of a relatively new caliber, smartly decided to create another one that gave the FBI both the performance and capacity they wanted in addition to smaller pistols, as mentioned earlier. Even the venerable 9mm and .45 ACP calibers benefitted from the then-recent development of smokeless power when they were created, which was purely a matter of timing and circumstance, and likewise .40 S&W benefitted from timing and circumstance (although it does have some points in its favor).
From the FBI's point of view, they had already invested much research into what they wanted in a pistol caliber, so they went along with it in order to get the most optimal--for them--caliber available. Not only that, it was new, and to many people newer means better. I imagine that there was also some internal pressure to use a caliber that they pretty much specified.
Capacity is perhaps a criteria to the making of the .40,
That and the size of frames and grips. .40 S&W basically stuffs a .45 ACP level of performance (in the areas that the FBI emphasized) into a smaller cartridge that has some of the advantages of 9mm, as well.
but this alone wouldn't not warrant any desire to spend a whole lot of money on something that we can already do with existing an existing technology. Am I right?
They had to justify the time and money they had already spent by using what they helped create. They could have chosen to go with .45 ACP or high-penetration 9mm, but at that point, they probably thought "Why not use .40 S&W because it has everything we happen to want?"
About penetration:
physics, and simple physics at that, dictate that the heavier the object, the harder it will be to stop that object with say... any one given object (like a block of wood of any certain density).
Weight is not the only factor--there are also sectional density (of which weight is a part) and velocity.
155gr can only be pushed up to the 980fps FBI criteria because any higher reaching over 1k fps would require more power, thus making it more recoil heavy, thus defeating the whole purpose of not using the almighty 10mm.
What?
The "10mm Lite" load they used had 180 grain bullets pushed at a similar velocity, I believe. .40 S&W was meant to match these ballistics using a smaller case, although if I remember correctly the FBI initially went with a lighter 165 grain bullet and a higher velocity in order to provide a similar amount of momentum. Now, of course, they're back to using 180 grain bullets, but at velocities over 1000 fps. I don't know where you're getting your information from. The load you describe is similar to a heavy 9mm load, which would defeat the purpose of using a different caliber altogether. No, the FBI wants the increased performance, and that's what they get.
But the .45 acp can accomplish this given velocity with a heavier bullet (185gr)
So can .40 S&W, and it does so in smaller pistols with 4" barrels, while .45 ACP suffers somewhat in barrels under 5" long.
and not require a heavier charge that will raise recoil,
How? If it has more energy and momentum, hypothetically speaking, then it needs a heavier charge--you don't get something for nothing as long as you're not being wasteful.
therefore making it more efficient in terms of penetration, right?
Not right at all. A 180 grain .40 S&W bullet has about the same sectional density as a 230 grain .45 ACP bullet, but it's as fast as a 185 grain .45 ACP bullet, so it will generally penetrate better. Much depends on their expansion characteristics, which can be tailored to the requirements, but putting that aside for the moment, when penetrating barriers .40 S&W is always going to have a smaller section, which in simple terms is easier for its momentum to push through things. You could always use 230 grain bullets in .45 ACP to equalize sectional density, but then you'll lose out on velocity.
Keep in mind that recoil was an issue to that the FBI needed to address.
Some of the agents couldn't handle hot 10mm loads, but that doesn't mean they now use weak .40 S&W loads like the one you described, either.
People say that the .45 may exhibit more recoil, but when you really get into the bullets and it's loads, the .40 can be more recoil heavy. It just depends on how the cartridges are loaded.
The cartridges contain a similar amount of energy. The main difference is that .40 S&W bullets accelerate more quickly, which makes people describe its recoil as "snappy," but it's not more actual recoil than you'd get from .45 ACP. Apparently the vast majority of FBI agents can handle it alright, so they'll take that tradeoff for smaller, lighter pistols (another major reason .40 S&W feels snappy when fired) and higher round capacity (meaning greater total firepower).
If anyone thinks I missed something here, please let me know
Just some simple physics.
The .45 can do it too! Why not the .45 acp then?
There's gotta be more to it
It has all been explained already. Let me ask you why not .45 Colt, which .45 ACP basically replaced? Why did they even bother to create .45 ACP in the first place when .45 Colt can do everything it can? The reasons were similar to the ones discussed here regarding .40 S&W, except that the reasons for creating .45 ACP were fewer.
