Pistol

The 1911A1 pistol is the backup weapon of all survivors. It is also the only weapon they can use when knocked down, although with a slower rate of fire and decreased accuracy. Besides the minigun, the pistol(s) is the only weapon that has infinite ammunition. However, they are still limited to a capacity of 15 rounds.

Even though they are meant as emergency weapons, the pistols make great secondaries, or even primaries for hunting rifle and shotgun users. They pack a punch slightly greater then that of the assault rifle, and possess above average accuracy.

Dual-wielding
If a second pistol is found, they can be dual-wielded. Second pistols are placed periodically from the Director, and can also be picked up from fallen team mates. This allows for twice the ammo capacity, as well as a slightly faster rate of fire. The downside of having two pistols is that it takes slightly longer to reload. When dual-wielded, the pistol in the left hand will not have a light.

Tactics
Pistols can be quite effective in the right hands. However, to be an effective pistol user, you must be accurate; try to crouch when the situation permits, as it will tighten your crosshairs and accuracy. The pistols have great accuracy, and a pistol user must take advantage of this. When using a shotgun, it is a good idea to use pistols for the farther away targets. In certain situations, switching to pistols may be a better option then waiting for your reload. When a teammate gets hit by a Hunter or a Smoker, draw your pistols and open fire. This will often kill the boss Infected faster than waiting for the reload, reducing the damage your buddy takes.

Trivia

 * The name "Colt" is often used as a name for generic .45 1911 pistols. However, even during the days it was first issued, Colt was far from the only manufacturer to produce them. Modern 1911s are made by a multitude of manufacturers, including Sig, Smith and Wesson, Wilson Combat, Kimber, Springfield Armory, Las Baer and Rock Island Armory.
 * The pistol is produced by the fictional company "Finleyville Armory." The name is derived from the Pennsylvania borough of Finleyville and may be meant to sound like Springfield Armory, a manufacturer of several kinds of popular 1911 pistols.
 * An actual single stack 1911 (which is what the in game model is based off of) uses 7,8 or 10 round magazines. There are 1911s that hold up to 14 rounds, but they are built on double stack (where the rounds are staggered to increase capacity) frames and are quite bulky. In fact, they are more often used for competition and range shooting then actual use.
 * The setup of the 1911 in Left 4 Dead is somewhat odd: It uses stainless steel components and a fairly modern frame, with a beavertail grip safety, extended thumb safety, rounded hammer and integral light rail, but has 1911A1 style sights. The original 1911A1 stock sights are much harder to use then modern 3 dot sights, or even blade, and are almost never used on modern 1911s.


 * Players can receive the Akimbo Assassin achievement by completing a campaign using only the pistol (or pistols) as firearms.