Senior Correspondent Rod Pascoe on a cartridge curio
A new cartridge will come into existence either by an individual believing they can improve on an existing concept with their own invention, usually referred to as a wildcat, or by a corporation looking to diversify the market with its own version of ‘the best cartridge ever made’. Fads and clever marketing will see some rise in popularity while others won’t be so lucky.
Look at how everyone, shooters and gun-makers alike, jumped on the 6.5mm bandwagon after the success of the 6.5 Creedmoor. Yet it was the demand of law enforcement agencies in the US, faced with a specific problem, which brought the .40 Smith & Wesson (S&W) cartridge into existence in 1990 but where is it now, just 35 years on?
In 1986 a number of Federal Bureau of Investigation officers were involved in a ‘shootout’ with two bank robbers in Miami, resulting in two agents dead and another five wounded. What followed was an extensive process of testing 9x19mm Parabellum (9mm Luger) and .45 ACP ammunition which would eventually be used in self-loading pistols to replace their current revolver.
The FBI determined the self-loading pistol offered two advantages over the revolver in increased ammunition capacity using double-stacked magazines and quicker reloading. Although satisfied with the performance of its .38 Special +P 158-grain lead semi-wadcutter hollow-point ammo in their service revolvers, investigations into the Miami incident revealed that while an agent had fired a well-placed shot on one of the perpetrators, it failed to reach any vital organs and the shooter continued to fire, killing the officer. That shootout changed the way US law enforcement looked at its handguns and ammunition, all based on the failure of a single bullet to stop one of the crooks.
The FBI developed a series of tests with 9mm Luger and .45 ACP ammo, involving eight scenarios using ballistic gelatine covered with various materials ranging from soft to hard they believed reasonably represented the kind of situations their agents would face in shooting incidents. When it comes to terminal ballistics of modern defence handgun projectiles, there’s been continuing disagreement over effectiveness of slow-moving, heavy projectiles (as in the .45 ACP) over faster-moving, lightweight bullets like the 9mm Luger.
This argument apparently began when US soldiers armed with .45-calibre 1911s faced Germans firing 9mm Lugers in World War One. The arguments continued after World War Two when some federal, state and county law enforcement agencies adopted 9mm pistols as their duty sidearms, in the belief they’re easier to shoot accurately than heavier calibres. So where does the .40 S&W fit into this story?
During testing of the 9mm Luger and .45 ACP ammunition, one of the FBI research team decided to include the 10mm Auto cartridge, supplying his own pistol and hand-loaded ammunition he used for target shooting. FBI tests revealed the 170-180-grain jacketed hollow-point 10mm bullet, moving between 900-1000 feet per second (fps) with a reduced target load, achieved similar terminal ballistics without the heavy recoil of 10mm factory-loaded ammo operating between 1300 and 1400fps with a lighter bullet. As a result, the FBI contracted Smith & Wesson to design a handgun, based on its existing large-frame S&W Model 4506 .45 ACP pistol, that would reliably function with the FBI’s reduced-velocity 10mm Auto cartridge.
But S&W suggested a different plan. They realised that downsizing the 10mm full-power, high pressure ammunition to meet the FBI’s medium-velocity specification meant that using less powder resulted in more airspace in the case. They found that by shortening the case to remove unused airspace, the 10mm case would fit their medium-frame 9mm handguns and, loaded with a 180gn jacketed hollow-point bullet, would produce the same ballistic performance as the FBI’s reduced-velocity 10mm cartridge used in testing.
S&W then teamed-up with Winchester to produce a new cartridge (the .40 S&W) which was the compromise between a fast lightweight bullet and a slow heavy one with a cartridge that fits medium-sized pistols. This was the solution to the problem the FBI and others were looking for.
The .40 S&W cartridge was launched in January 1990, along with the new Smith & Wesson Model 4006 pistol, although it was a while before the pistols were available to buy. Meanwhile, Austrian manufacturer Glock had pistols commercially available ahead of Smith & Wesson with guns chambered in .40 S&W (the Glock 22 and 23) which were announced a week before the S&W 4006.
Glock’s rapid introduction was helped by it already having a pistol chambered in 10mm Auto (the Glock 20) just a short time earlier. Since the .40 S&W uses the same bore diameter and case head as the 10mm Auto, it was simply a matter of adapting the 10mm design to the shorter 9x19mm Parabellum frames. The new guns and ammunition were an immediate success, with pistols in the new calibre embraced by several law enforcement agencies around the US, including the FBI, which adopted the Glock in .40 S&W in May 1997.
The .40 S&W (10.2x22mm) is a straight-sided rimless pistol cartridge using 0.40 of an inch diameter or 10mm bullets ranging in weight from 105 to 200 grains. Its case length and overall cartridge length are shortened, but other dimensions except for case web and wall thickness remain identical to the 10mm Auto, though unlike that one the .40 S&W uses small pistol primers. Both cartridges headspace on the mouth of the case, meaning in self-loaders they’re not interchangeable. Fired from a 10mm self-loader the .40 S&W cartridge will headspace on the extractor and the bullet has to jump 0.142” or (3.6mm) of freebore.
The problem with the .40 S&W
For a short time in the late 1990s the .40 S&W was flavour of the month for both law enforcement and civilian use. Then something happened. It was discovered that when analysing hits on human bodies the 9mm, .357 SIG, .40 S&W, 10mm Auto and .45 ACP all produced about the same real-life results, so the myth that there’s a single, magical ‘one-shot’ cartridge was dispelled. Apart from a shot to the head, it was revealed most perpetrators had to be struck at least twice before their aggressive and dangerous actions ceased.
The argument here is that if two hits of 9mm is going to give the same result as two hits with either a .40 S&W or .45 ACP, why bother issuing handguns chambered for the bigger calibres? As a result, many law enforcement departments began transitioning back to the 9mm and, in 2015, the FBI announced they were also going back to 9mm ammunition, after a study showed the newer 9mm ‘defensive’ ammo was just as effective for law enforcement applications as the .40 S&W.
After more than 20 years of issuing the .40 S&W, the FBI transitioned their agents to the Glock 17 and 19 models in 9mm Luger, a change of heart which contributed to the .40 S&W’s decline in popularity with law enforcement across the US. Furthermore, during the 20 years the .40 S&W cartridge was in service, the FBI changed its thinking about the primary role of a projectile from being one of bullet expansion on hitting its target to one of penetration, the reason behind the agency looking for a new cartridge in the first place. Ballistic engineers figured out how to use the velocity of the 9mm in conjunction with modern bullet construction techniques to build ammo that’s up to FBI standards, eventually settling on the Winchester 147-grain hollow-point subsonic.
Conclusion
There are several schools of thought when it comes to the suitability of various defensive-handgun cartridges. Some argue on the side of calibre, some expansion, some penetration and others energy. Yet velocity is key, being the element of the equation which allows a bullet to expand, penetrate and do its job.
FBI follow-up testing found there’s such a small difference in terminal performance between the 9mm, .40 S&W and .45 ACP, and factors such as the connection between shooter and handgun, ammo capacity and shot placement are more important. It would seem it’s taken bullet engineers about 30 years to level the playing field between these cartridges, and the FBI the same amount of time to realise something now considered obvious.
By going with the 9mm the FBI gets the terminal performance it desires, with more capacity in a handgun that’s easier and faster to shoot accurately. And there’s always been an issue that new recruits undergoing handgun training should be able to shoot quickly and accurately with a self-loading pistol to pass their course, something made more difficult with the higher recoiling .40 S&W ammo. At time of writing and following the lead from the US, some Australian federal, state and territory law enforcement agencies are in the process of transitioning from .40 S&W to 9mm Luger handguns.