So…What’s so great about the .40 S&W?
Intro: What caliber a person feels is the “best” for any particular usage in a handgun is a very complicated and touchy subject for firearms geeks. It is a potentially confusing topic to those who are just getting into firearms. It is arguable that there is already a good caliber or two (or three) for any potential purpose. However, emotions get involved in the discussion at times and opinions run strong. Any handgun is a compromise; carrying around a rifle would be better. But it is impractical to take your AR out on the town. So the question with a handgun becomes ‘what weapon can I comfortably carry and still have an effective means of defense?’ The decisions one has to make when carrying a handgun are the compromises between power, portability, fit, and capacity. Everything is a tradeoff…
No, not that Miami…
The .40 S&W – Wow, what a tale. The origin of the .40 S&W lies in a disastrous shootout in Miami in 1986. Several FBI agents attempted to perform a felony arrest on two bank robbers. Many, many things went wrong in that event, but one of the things that came out of it was the powers-that-be determined the 9mm Luger (.38 caliber) was just not enough gun (this may seem familiar if you have read “what so great about the .45 ACP). One of the criminals was fatally shot several times (several of the shots were non-survivable individually) but he continued to function and return fire for several minutes before he had the good grace to die. Essentially his will to do evil kept him going long after most would have been assuming room temperature. This was blamed on the 9mm which had become the FBI’s service cartridge several years prior to this incident.
Detour: In the beginning of the FBI the FBI did not have formal arrest powers and sometimes relied on being deputized by a local sheriff in order to directly carry out their duties. The FBI was primarily an investigative organization, and they originally were tasked with investigating white collar organized crime. Then in the 1930’s the automobile bandit was born and they began to be the G men we know them as today (incidentally leading to the .38 Super and the .357 Magnum) because they could chase the criminals across state and county lines (where Sheriffs and State Police had jurisdictional difficulty). However, it is worth noting that the FBI did not originally have a strong firearms culture, they did not recruit from the military or even county law 
enforcement as a rule; the agents were more likely to be accountants by trade than old west Earp types. As a result, In the beginning the FBI was not too fussy about what firearm its’ agents carried, or presumably even if they did. Gradually they adopted the .38 Special snub nosed revolver, or the large .357 Magnum revolver, whichever the agent preferred and it was this way for almost 50 years. In the early 1980’s the whole organization changed their primary sidearm to the the 9mm round in a S&W 459 pistol, presumably for training and logistics reasons. The 9mm Luger was a battle proven round, the agents were fairly happy. Then the Miami Shootout happened. Back to the story…
Col. Jeff Cooper
So, after some testing, where initially it seemed they might be leaning to the .45, one of the shooters involved in the testing offered to test his personal 10mm Auto and his handloads. When the dust settled the FBI decreed that the new official sidearm for the FBI in 1989 would be the S&W 1076 pistol chambered in 10mm Auto. Firearms legend Jeff Cooper was instrumental in the 10mm’s design and it was introduced in 1983 with the Bren Ten pistol (an interesting story for another time). Col. Cooper loved the 1911 pistol, and he loved the .45 ACP cartridge, but he was concerned that sometimes you needed more oomph. What he was looking for was .357 Magnum performance out of a semi auto pistol and the 10mm delivered. The Miami shootout seemed to support Cooper’s conviction. The thing was, many of the FBI agents couldn’t shoot it well, and didn’t like it because of stout recoil, and the large pistol chambered for it. Remember, most of them had went from the mild .38 Spcl. to the more powerful, but still pretty mild 9mm, the 10mm was a big increase in power (and recoil) and the pistol it was chambered in was a big pistol to hold and carry, especially concealed. So the FBI had special loads made that downgraded its’ performance. This FBI Load, or 10mm Lite, helped the recoil issue when shooting the cartridge, but not with carrying the gun.
Then, as gun folks do, some people at Smith & Wesson and Winchester ammunition started thinking that you didn’t need the 10mm case size to run that FBI Load, so they shortened the 10mm case, used the same bullet, now the cartridge would fit in a smaller (9mm size) framed gun, voila, in 1990 the .40 S&W was born. It took off like a whirlwind. It was a marketing coup. This was the first truly new widely acceptable cartridge for a semi-auto handgun in about 50 years. I remember the hype pretty well. It was going to be the best of both worlds. The Illinois State Police adopted it first and in 1997 the FBI decreed it to be the service cartridge, and the Glock 22 and 23 the official sidearm.
In practical terms what the .40 S&W attempts to do is bridge the gap between two sides in a very long standing debate. 9 mm vs .45 ACP. People who prefer 9 mm say that guns chambered for 9 mm have adequate power and higher capacity than guns in .45, and only hits count. People who prefer .45 believe bigger holes are always bigger and therefore, superior, and when you have a superior firearm all you need is 8-9 rounds.
The average .40 S&W load is more powerful than a run of the mill 9 mm load, and its’ designation starts with that all important number 4, so it has that going for it. Firearms chambered for .40 S&W typically only give up one or two rounds in capacity to the 9mm. It SHOULD be the best of both worlds. However, many law enforcement agencies report that the .40 has higher perceived recoil than the 9, OR the .45. When it comes to civilian use, a couple of trends are pretty clear at the moment: .40 Caliber pistols are fairly plentiful and can sometimes be purchased for less than a 9 mm, and .40 S&W ammunition is almost always available, but will cost a few dollars more per box. Average muzzle energy of several commercial loads of .40 S&W is 445 ft lbs (~600 J), so it is a slight step up in performance from the 9 mm; some of its’ hotter loads are above basic .45 acp performance. In practice it seems that the .40, instead of soothing the debate and winning people from both camps, actually threw gas on the age old fire.
If you carry a .40 because of increased power, this seems to justify carrying a .45 to the .45 carriers, because bigger is always bigger, and therefore, better. If you justify carrying a .40 for the increased capacity, then that justifies the 9 mm camp’s belief that capacity and follow up shot speed and accuracy are better than a marginally bigger hole. That usually puts the .40 S&W person in the position of defending their choice to everyone. Then again people who carry .40 S&W are usually more secure and well reasoned anyway, aren’t they? Right? Right? All snark aside, the .40 S&W is effective, and here to stay, and that is an impressive feat in the long term firearms market.
