The .40 S&W
The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Smith & Wesson and Winchester. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation's (FBI) reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) semi-automatic handguns. It uses 0.40-inch (10 mm) diameter bullets ranging in weight from 105 to 200 grains. In the aftermath of the 1986 FBI Miami shootout, in which two FBI special agents were killed and five wounded, the FBI started the process of testing 9×19mm Parabellum and .45 ACP ammunition in preparation to replace its standard-issue revolver with a semi-automatic pistol. The semi-automatic pistol offered two advantages over the revolver: increased ammunition capacity and increased ease of reloading during a gunfight.
The FBI was satisfied with the performance of its .38 Special +P 158 gr lead semi-wadcutter hollowpoint (LSWCHP) cartridge ("FBI load") based on decades of dependable performance. Ammunition for the new semi-automatic pistol had to deliver terminal performance equal or superior to the .38 Special FBI load. The FBI developed a series of practically oriented tests involving eight test events that they believed reasonably represented the kinds of situations that FBI agents commonly encountered in shooting incidents.
During tests of the 9×19mm and .45 ACP ammunition, the FBI Firearms Training Unit's special agent-in-charge, John Hall, decided to include tests of the 10mm Auto cartridge, supplying his own Colt Delta Elite 10mm semi-automatic, and personally handloaded ammunition. The FBI's tests revealed that a 170–180 gr JHP 10mm bullet, propelled between 900–1,000 ft/s, achieved desired terminal performance without the heavy recoil associated with conventional 10mm ammunition (1,300–1,400 ft/s).
The FBI contacted Smith & Wesson and requested it to design a handgun to FBI specifications, based on the existing large-frame Smith & Wesson Model 4506 .45 ACP handgun, that would reliably function with the FBI's reduced-velocity 10 mm ammunition. During this collaboration with the FBI, S&W realized that downsizing the 10mm full power to meet the FBI's medium velocity specification meant less powder and more airspace in the case. They found that by removing the airspace they could shorten the 10mm case enough to fit within their medium-frame 9mm handguns and load it with a 180 gr JHP bullet to produce ballistic performance identical to the FBI's reduced-velocity 10mm cartridge. S&W then teamed with Winchester to produce a new cartridge, the .40 S&W. It uses a small pistol primer whereas the 10mm cartridge uses a large pistol primer.
The .40 S&W cartridge has been popular with law enforcement agencies in the United States, Canada, Australia, and Brazil. While possessing nearly identical accuracy, drift and drop as the 9mm Parabellum, it also has an energy advantage over the 9mm Parabellum and .45 ACP, and with a more manageable recoil than the 10mm Auto cartridge. Marshall & Sanow (and other hydrostatic shock proponents) contend that with good jacketed hollow point bullets, the more energetic loads for the .40 S&W can also create hydrostatic shock in human-sized living targets.
Based on ideal terminal ballistic performance in ordnance gelatin during lab testing in the late 1980s and early 1990s, the .40 S&W earned status as "the ideal cartridge for personal defense and law enforcement". Ballistically the .40 S&W is almost identical to the .38-40 Winchester introduced in 1874, as they share the same bullet diameter and bullet weight, and have similar muzzle velocities.
The energy of the .40 S&W exceeds standard-pressure .45 ACP loadings, generating between 350 foot-pounds and 500 foot-pounds of energy, depending on bullet weight. Both the .40 S&W and the 9mm Parabellum operate at a 35,000 pounds per square inch SAAMI maximum, compared to a 21,000 pounds per square inch maximum for .45 ACP.
The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Smith & Wesson and Winchester. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation's (FBI) reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) semi-automatic handguns. It uses 0.40-inch (10 mm) diameter bullets ranging in weight from 105 to 200 grains. In the aftermath of the 1986 FBI Miami shootout, in which two FBI special agents were killed and five wounded, the FBI started the process of testing 9×19mm Parabellum and .45 ACP ammunition in preparation to replace its standard-issue revolver with a semi-automatic pistol. The semi-automatic pistol offered two advantages over the revolver: increased ammunition capacity and increased ease of reloading during a gunfight.
The FBI was satisfied with the performance of its .38 Special +P 158 gr lead semi-wadcutter hollowpoint (LSWCHP) cartridge ("FBI load") based on decades of dependable performance. Ammunition for the new semi-automatic pistol had to deliver terminal performance equal or superior to the .38 Special FBI load. The FBI developed a series of practically oriented tests involving eight test events that they believed reasonably represented the kinds of situations that FBI agents commonly encountered in shooting incidents.
During tests of the 9×19mm and .45 ACP ammunition, the FBI Firearms Training Unit's special agent-in-charge, John Hall, decided to include tests of the 10mm Auto cartridge, supplying his own Colt Delta Elite 10mm semi-automatic, and personally handloaded ammunition. The FBI's tests revealed that a 170–180 gr JHP 10mm bullet, propelled between 900–1,000 ft/s, achieved desired terminal performance without the heavy recoil associated with conventional 10mm ammunition (1,300–1,400 ft/s).
The FBI contacted Smith & Wesson and requested it to design a handgun to FBI specifications, based on the existing large-frame Smith & Wesson Model 4506 .45 ACP handgun, that would reliably function with the FBI's reduced-velocity 10 mm ammunition. During this collaboration with the FBI, S&W realized that downsizing the 10mm full power to meet the FBI's medium velocity specification meant less powder and more airspace in the case. They found that by removing the airspace they could shorten the 10mm case enough to fit within their medium-frame 9mm handguns and load it with a 180 gr JHP bullet to produce ballistic performance identical to the FBI's reduced-velocity 10mm cartridge. S&W then teamed with Winchester to produce a new cartridge, the .40 S&W. It uses a small pistol primer whereas the 10mm cartridge uses a large pistol primer.
The .40 S&W cartridge has been popular with law enforcement agencies in the United States, Canada, Australia, and Brazil. While possessing nearly identical accuracy, drift and drop as the 9mm Parabellum, it also has an energy advantage over the 9mm Parabellum and .45 ACP, and with a more manageable recoil than the 10mm Auto cartridge. Marshall & Sanow (and other hydrostatic shock proponents) contend that with good jacketed hollow point bullets, the more energetic loads for the .40 S&W can also create hydrostatic shock in human-sized living targets.
Based on ideal terminal ballistic performance in ordnance gelatin during lab testing in the late 1980s and early 1990s, the .40 S&W earned status as "the ideal cartridge for personal defense and law enforcement". Ballistically the .40 S&W is almost identical to the .38-40 Winchester introduced in 1874, as they share the same bullet diameter and bullet weight, and have similar muzzle velocities.
The energy of the .40 S&W exceeds standard-pressure .45 ACP loadings, generating between 350 foot-pounds and 500 foot-pounds of energy, depending on bullet weight. Both the .40 S&W and the 9mm Parabellum operate at a 35,000 pounds per square inch SAAMI maximum, compared to a 21,000 pounds per square inch maximum for .45 ACP.