August 24, 2012:
The U.S. Marine Corps has ordered 12,000 .45 (11.4mm) caliber pistols (for $1,900 each), mainly for use by its SOCOM (Special Operations Command) and recon troops. These MARSOC (Marine Special Operations Command) troops have, like the army, navy, and air force components of SOCOM, quietly replaced most of their 9mm pistols with .45s. For the last few years the marines have been supplying their special operations troops with older M1911 model .45s, refurbished (or built from scrounged up parts) in a marine-run facility. The M1911 .45 caliber ACP is a 1.2 kg (2.45 pound) 210mm (8.25 inch) long weapon with a 127mm (5 inch) barrel and a 7 round magazine. Compared to the current American M9 9mm pistol the .45s have more hitting power, while the M9 is a bit more accurate at up to about 50 meters.
The new marine .45s are not the old M1911A1 model but the more modern Colt CQBP (Close Quarter Battle Pistol), which uses the same ammo as the M1911A1 but has a number of improvements that make the weapon more reliable, flexible, and accurate. The CQBP holds eight rounds, is built to resist salt water corrosion, accept rail mounted accessories, and so on.
There are several improved .45s available because of demand from police departments and government agencies (like the FBI). In the 1990s SOCOM adopted the Heckler and Koch Mk 23 SOCOM model. This is a 1.47 kg (3.2 pound) .45 pistol with a 12-round magazine and the ability to carry a silencer. It is expensive, at $2400 each. Loaded with a silencer and laser aiming device the Mk23 weighs 2.29 kg (5 pounds). The Mk23 is a precision weapon, capable of accurate fire at 50 meters (51mm/two inch shot groups). The Mk 23 is for offensive operations while the lighter and cheaper USP Tactical model was later introduced for personal protection and other duties not requiring the heavier Mk 23.
Over the last decade American troops in Iraq and Afghanistan discovered, through combat experience, what types of weapons worked best at close range to take down the enemy. It was the same with SWAT teams and commandos all over the world. When conducting a raid and finding yourself up close and personal with someone trying to kill you, there is a need for a heavy caliber pistol or a shotgun (firing 00 shot or slugs). The premier pistol for ensuring you take down someone is still the .45 caliber (11.4mm) or .40 caliber (10mm, but only with a heavy bullet) pistols. These weapons are light and handy, compared to assault rifles or shotguns, and have a long history of quickly taking down an armed and determined foe.
As the U.S. Army Special Forces discovered, if you are well trained and know what you are doing, you should carry a pistol, in addition to your rifle. But not the official issue (since 1985) M9 9mm pistol but something with a bit more stopping power. The Special Forces prefer new model .45 caliber pistols, although 10mm weapons are also popular. The reason for this is that you are most likely to be using the pistol indoors, where your target is going to be really close. You want to knock him down quickly, before he can get at you with a knife or even his hands. Many troops are getting their own pistols and most commanders have been lenient on this issue. The same applies to shotguns. Although the army and marines have bought a lot of them (the Benelli M4 Combat Shotgun is a particular favorite), there never seem to be enough of them for some units (that spend a lot of time raiding buildings in hostile neighborhoods).
The troops also appreciate getting the most realistic urban combat training possible. This included the use of modified (to fire slower bullets that sting but don't break the skin) pistols and rifles in "kill houses." Here, training can be carried out with live ammo. Kill houses are also equipped with vidcams and the troops particularly like to watch the vids of their performances. Seeing your mistakes apparently makes it easier to correct them. For close combat, a weapon with stopping power is no good unless you know how to use it.
All of this stuff is old news to the Special Forces, which have been doing all of this for years. But the army and marine grunts are smarter, better trained, and better led than at any time in the past. That's always been the description of the Special Forces, so it's not surprising that the better quality "regular infantry" are starting to adopt Special Forces techniques. SWAT teams everywhere pay attention to this military experience, as they often get involved in the same kind of close combat. SWAT operators are a large market and driving the development of new equipment, which is often later picked up by military personnel.
The U.S. military adopted the 9mm pistol in 1985, largely to standardize ammunition. All other NATO states used 9mm for pistols. The U.S. also noted that most 9mm pistols were carried by officers and support personnel, who rarely used them in combat. SOCOM came into being a few years later and immediately began planning to bring back .45 pistols. Actually, many Special Forces and SEAL operators never gave up using the .45, as it was the ideal pistol for many commando operations.