While I enjoy shooting my SiG 2340 with it's 357SiG barrel I'm not sure why either 357SiG or 40S&W were ever developed. Neither round does anything not done by other calibers.

So my question is, "Other than giving the manufactureres a reason to push new pistol sales in the LE market (which also drives sales in the consumer market) what advantages do 40S&W or 357SiG provide that couldn't be achieved with one of the existing calibers?"

Interesting observation and one I have some agreement.  The development of the 40 can be traced back to the FBI "lite" 10mm loads they developed after the Miami shootout.  The FBI blamed, at least partially, the 9mm for their problems that day.  A mistaken assumption in my view, but that's another subject.  Combined with an American prejudice against "foreign" calibers, a weakness for fads (yes, gun owners and LEO's are subject to fads just like your teenagers), American "magnumitis", and the desire for something "new" and the 40 took off.  

Nothing wrong with either caliber, but they won't do anything a properly designed 9MM or 45 wont' do.  And none of them will do anything if you miss.  And no handgun caliber has yet become the one armed death ray that seems to be the holy grail.  

Interesting to see the comments.

Power in a smaller package is the answer.  The 10mm had too much recoil for the masses, and it required a large frame gun.  The FBI started to download the 10mm, and some bright guy figured out that you  could get the same ballistic performance out of a shorter case.  The shorter case had the advantage of being able to fit in a medium frame (i.e. 9mm size) handgun.  The combination resulted in a weapon more powerful than a 9mm, but with more ammo capacity than a .45, housed in a pistol the size of a 9mm.  The California Highway Patrol adopted it almost immeadiately, and the FBI and many other 9mm users went to it.

The .357Sig is basically the same cartridge firing a smaller caliber bullet at a higher velocity.  It gives better penetration, and the caliber is still the same as the 9mm/.357mag of police favor.  Considering that most police shootouts these days either have a suspect in or behind a car, penetration is a big plus.  The old .357mag has always been the #1 one-shot-stop cartridge.  This was an attempt to get that performance in a modern autoloader.  Like it's .40cal cousin, it fits in the same medium frame guns with the same capacity mags.  The Virginia State Police (highway patrol) were the frist to adopt it, and many others have also followed suit.  

Both are great rounds, and the obvious advantage to anyone owning one, is they can normally switch to the other if they feel like it.  There were plenty of other rounds that have the same, or better performance.  It's just that these two combine several other features, like the size of the gun to handle them and magazine capacity, that the others just don't.

Ross

 

If being able to switch ammo/bbl. and using the same magazine is Snake Oil, I'll take two!!!

That's a unique feature between these two calibers, anyway.
More power/firepower in the smaller package is also true.
Don't forget that the U.S. Border Patrol uses the .40/155 as it outperformed both the 9mm & .45 in tests they were interested in.

I don't think they're Snake Oil.

The fact that someone, particularly Law enforcement, just doesn't carry any weight. Law Enforcement Agencies are famous for making totally stupid decisions based on the political or financial interests of some bigwig. What's best for them folk out on the street somehow seems to get lost all too often.

Some good points are the ability to have one pistol, three barrels and all other components the same. But how often is that capability used? Name one department that issues one frame and three barrels? That's a neat feature but really adds no value.

I have the SiGPro 2340 and both barrels. I shot the 40S&W for a while, and the 357SiG a little bit longer. And the 357SiG is fun to shoot. But it's also expensive. And neither the 40S&W or the 357SiG are good candidates for reloading (sure some folk do it). So basically I have a pistol that shoots non standard, expensive ammo that does nothing that I can't do with either a 357Mag or 45.

As I said, I just don't see any real advantage to anyone except the gun and ammo manufacturers.

The .40 to me is the child of the waning 10MM. As a package, it seems like it splits the capacity of a 9MM with the thump of a .45. I never jump on latest trends, just for the sake of it. But I try to keep up with the latest "fashions", at least acknowledgement. And the .40 is picking up steam, so LE or not, someone is buying.

Quoted: I have the SiGPro 2340 and both barrels. I shot the 40S&W for a while, and the 357SiG a little bit longer. And the 357SiG is fun to shoot. But it's also expensive. And neither the 40S&W or the 357SiG are good candidates for reloading (sure some folk do it). So basically I have a pistol that shoots non standard, expensive ammo that does nothing that I can't do with either a 357Mag or 45.

I'm curious why you think the .40 isn't a good candidate for reloading.  I've been reloading it for years, mostly for convenience and cost savings.  The .357 SIG with its bottleneck case requires lubing, which is a pain in the neck.  But its performance, if not duplicates, then closely approaches the .357 Magnum's.  Some people just prefer semi-autos, and to have a cartridge that would do that in a semi-auto has been the Holy Grail of some folks for quite a while.

As I said, I just don't see any real advantage to anyone except the gun and ammo manufacturers.

10mm history aside, I think the .40 was an attempt to develop an effective self-defense cartridge that would rival the performance of the .45 without the size.  Many people feel that the 9mm Luger just isn't a very potent round; the '86 FBI Miami firefight was a dramatic example.

Quoted: Quoted: I have the SiGPro 2340 and both barrels. I shot the 40S&W for a while, and the 357SiG a little bit longer. And the 357SiG is fun to shoot. But it's also expensive. And neither the 40S&W or the 357SiG are good candidates for reloading (sure some folk do it). So basically I have a pistol that shoots non standard, expensive ammo that does nothing that I can't do with either a 357Mag or 45. I'm curious why you think the .40 isn't a good candidate for reloading.  I've been reloading it for years, mostly for convenience and cost savings.  The .357 SIG with its bottleneck case requires lubing, which is a pain in the neck.  But its performance, if not duplicates, then closely approaches the .357 Magnum's.  Some people just prefer semi-autos, and to have a cartridge that would do that in a semi-auto has been the Holy Grail of some folks for quite a while. As I said, I just don't see any real advantage to anyone except the gun and ammo manufacturers. 10mm history aside, I think the .40 was an attempt to develop an effective self-defense cartridge that would rival the performance of the .45 without the size.  Many people feel that the 9mm Luger just isn't a very potent round; the '86 FBI Miami firefight was a dramatic example.

Well, Miami and LA have been hashed over and used as justification for most everything. So I really don't think theyprove very much except that beauracratic interference will get folks on the line killed every day.

The 40S&W is not a good candidate for reloading IMHO for a couple major reasons. First, it's very subject to developing overpressures under a number of different scenarios. If the seating is too deep, the crimping too tight, then charge slightly too hot, all can lead to serious overpressures. I know that you can have similar problems with outher calibers, but the margins of error are far closer on the 40S&W than on any others I've worked with.

The second big reason is the wall thickness. 40S&W cases are relatively thin walled to begin with. In resizing, you flex the walls which reduces the strength even more. Again, this can lead to serious problems.

I trust that you are careful enough not to make any mistakes, but I know all too many handloaders that are not really careful and that love pushing the envelope.