Submachine Gun

The Uzi submachine gun deals light progressive damage. Holds 50 rounds with 480 in reserve. It has enough accuracy to shoot at medium range. It has noticeable stopping power. The main drawback to the submachine gun is the high rate of ammo expenditure; most Survivors using a submachine gun will run out of ammo partially through a level if they aren't conservative with their shooting. The submachine gun is great for medium-ranged closed-quarters such as large warehouses and apartments. Its high rate of fire and penetration make it a ranged alternative to the short-ranged shotgun.

Tactics

 * Fire in small bursts. This keeps accuracy up and prevents you from shooting zombies when they're already dying.
 * Move forward, crouch, shoot, move forward again. Again, better accuracy, this also gives your team an opportunity to shoot over your head if an Infected comes into your blind spot.
 * Learn when not to shoot. Your ammo needs conservation. Let the guy with the shotgun take point and use your bullets to cover him.
 * When shooting, aim for zombie feet and move the cursor up the zombies body. The zombie slows down from the leg shot and then gets shot in the head.
 * Feet shots limit friendly fire.
 * The Uzi can shoot through damaged doors without risking further damage.
 * When a zombie smacks you, your accuracy drops. When you need to make a shot (i.e. to save a friend who's being strangled) you will need to knock the Infected off you first.
 * The accuracy of the Uzi lets it hit enemies at a greater distance.
 * Save pounced or snared teammates at long range by shooting the Hunter, the Smoker, or the tongue.
 * Take out long range threats before the rest of the team pushes on.
 * Reload often. The high rate of fire on the Uzi means that the 50 round magazine will run dry fairly quickly. The last thing your team needs is one less gun during a panic event.
 * One advantage the Submachine Gun has over its bigger brother, the Assault Rifle, is its higher ammo capacity and higher rate of fire. This is particularly useful to more easily decimate a hallway of zombies, while the Assault Rifle is best shooting at longer ranges than in corridors. One player can use the Uzi while the other with the Assault Rifle can conserve ammunition in close quarter hordes.

A recent glitch or Easter egg in the game has been discovered which allows the Uzi to shoot an entire clip of ammo in one shot. You can accomplish this by switching to your pistols and holding melee, switching back to the Uzi (while still holding melee), then holding down shoot along with melee, after about 5 to 7 seconds letting go of melee while still holding shoot. If done correctly it should allow you to do the specified glitch or Easter egg. Using this glitch with the assault rifle can make the "cr0wnd" achievement very easy, simply aim at the witch's head use the aforementioned glitch to one-shot her.

The glitch is mainly called the "Powershot". It's one of the only glitches of taking down Tanks and Witches really fast. You can also do this glitch with a Assault Rifle. It has been patched on the PC version but on the 360 version you can still do this. On Expert the glitch is useful for taking down a Tank but it requires about around 7 or 8 shots.

Left 4 Dead 2
In Left 4 Dead 2, the new SMG appears to be a suppressed MAC-10 SMG. The suppressor appears to have no affect on the Infected, as they can still be seen running towards the players while he is firing at other enemies.

The L4D SMG is still in the game, as seen below.

Trivia

 * The ammo count is 480, hinting that the Uzi may have originally used its real life capacity of 32 rounds.
 * Left 4 Dead ' s Uzi has a much higher rate of fire than the actual Uzi, resembling the Micro Uzi variant.
 * The SMG is based on Counter-Strike ' s MP5N submachine gun. Its "price" in the gun's weapon file is the same as the MP5's, and it references the MP5 in its "animation" listing.
 * Occasionally when Louis picks up the Uzi, he states "Oh, MAN! This is just like Counter-Strike!"
 * If you look close enough, the Uzi's bolt doesn't move when firing. In reality, this is how the Uzi works by using open bolt action. Open bolt action means that in default cocked position, the bolt is open, when the gun is fired, the bolt is released, hits the firing pin, and gets recocked by the bullet's gas
 * The Left 4 Dead 2 variant appears to be silenced, though this does not seem to have any effect on gameplay. It is only seen from now in Left 4 Dead 2's E3 2009 demo.