Pump Shotgun

"Shotgun! Alright folks, I'm on crowd control."

- Francis

"Grabbing the shotgun of love!"

- Ellis

The Pump Shotgun deals heavy damage to a single enemy or lighter damage to many, in a spread. It holds eight shells with 128 in reserve. The spread of the 10 pellets in a shell can take down multiple Infected at a time. This often makes it better at handling Hordes than the Submachine Gun or Pistols. It reloads about two shells per second and fires one shell per second. The spread of the Pump Shotgun makes Pistols better than it for ranged encounters.

All shotguns allow topping off the magazine on the fly, and the reloading process can be stopped to handle sudden threats. However, if you are reloading when empty, you will manually pump the shotgun at the end of the reload, regardless of whether it finished or was interrupted. A good trick is to interrupt an empty reload after the first shot by clicking the fire button and then reloading again, as you have gotten the racking animation out of the way and can immediately fire if a threat appears. Another tip is just to reload constantly and always keep at least one shell loaded.

Like the Chrome Shotgun, Auto Shotgun, and Combat Shotgun, the Pump Shotgun can kill the Witch with one hit if all the pellets strike her head before she rises, making it useful for getting the "Cr0wnd" and the "Witch Hunter" achievement.

Tactics

 * While being attacked by Hordes, it is best to do a melee attack after each shot to push back Infected while pumping, to increase survivability.
 * You can melee as you reload instead of just standing there, waiting to finish reloading. This helps with keeping the Infected at bay.
 * Team members with Pump Shotguns should be at the front to reduce the chance of friendly fire.
 * If you're trying to help someone who is surrounded on any difficulty levels aside from Easy or Normal, switch to the Pistol. If you try to use the Pump Shotgun, you're most likely going to end up dealing more damage than the Infected themselves. If you must use a Pump Shotgun to rescue a surrounded teammate, keep the cross-hair off the teammate to kill Infected with the spread.
 * When attempting to headshot a Witch, it's best to have the top line on the cross-hair aimed for the Witch's forehead. This tactic, however, only works about 85% of the time.
 * If your teammate is being attacked on the other side of a thin wall, you can use the Pump Shotgun to shoot through the wall to save them.

Pros

 * Extremely powerful early in the game, capable of going though hordes of zombies.
 * A lot more powerful at close range compared to the Submachine Gun.
 * Due to a low rate of fire, it is easy to control and does not run out of ammo as quickly as other guns.
 * Can take out Special Infected (especially Hunters) faster than the Submachine Gun at close range.
 * Low rate of fire means it can reduce the incidence of friendly fire accidents.
 * Shot dispersion means it can take out multiple Common Infected simultaneously.
 * Great for tight, narrow spaces like choke points in buildings.

Cons

 * Slow reloading time since each shell in the gun must be reloaded individually, although it can still be fired during the reloading sequence.
 * Extremely inaccurate and ineffective at long distances due to its wide shot dispersion and loss of ballistic efficiency.
 * Strikingly less effective against the Tank and other Special Infected at medium to long ranges.
 * Low rates of fire and shot velocities makes it difficult to hit fast moving deflection targets.
 * When grabbed by a Smoker at long range, it is nearly impossible for a player to kill him unaided before being dragged off.
 * On higher difficulties, friendly fire becomes a serious problem. On Expert, one shot can incapacitate a teammate.
 * The loose spread Pump Shotgun have making it almost impossible to cr0wn the Witch sucessfully compared with the other shotgun.

Left 4 Dead 2
The Pump Shotgun returns with a new model. Compared to the Chrome Shotgun, it has a higher DPS due to two more pellets per shell (250 damage/s (If every pellet hits), four more than its Chrome counter-part) but a larger spread. Unfortunately, the Pump Shotgun's reserve ammunition has been dramatically reduced from 128 shells to 56, making every shot valuable.

Behind the Scenes
An unusual ammo counter for the Pump Shotgun's magazine is in the game's files. It shows eight shotgun shells. There are two versions; one for an empty magazine and one for a full one. This has never been seen in any footage, which means that it is much earlier than the footage shown. This seems to hint that in very early versions of the game, the player ammo count would be shown with a physical representation of how much ammo is left in the magazine. It has a resemblance with Medal of Honor: Allied Assault ammo counter.

The Pump Shotgun is based on Counter-Strike ' s M3 pump-action shotgun. Its "price" in the gun's weapon file is the same as the M3's, and it references the M3 in its "animation" listing. The M3's firing sound is played when Francis fires the Pump Shotgun in the first Left 4 Dead teaser, released in January 2007.