M60 Machine Gun

The M60 General Purpose machine gun is a special tier weapon that made it's debut in the Left 4 Dead 2 DLC, The Passing. It carries only 150 rounds and after that's depleted, it is dropped. The Survivor will then revert back to their secondary weapon, much like with the Grenade Launcher.

Pros

 * Deals more damage, so killing Special Infected, mainly the Tank and Witch, is quicker.
 * It can mow down many Infected faster, thus making taking out a horde quicker and easier.
 * The high capacity of rounds without reloading can really help when faced with a large swarm of infected.
 * With Incendiary Ammunition or Explosive Ammunition the high firepower really shines.

Cons

 * You can't refill the ammunition, so when you are out of ammo for it, it will be dropped.
 * Seeing how it's a Special Tier weapon, chances are it's going to be a rare weapon to find.
 * It might slow you down and might also impact your melee.
 * Accuracy may be diminished at longer ranges.

Tactics

 * Using a bile bomb along with the M60 can really help to rack up the kills when faced with a large amount of infected in an open area.
 * When not facing a horde or a Tank switch to your melee weapon or sidearm to avoid wasting the ammunition on a few scattered infected.
 * Like the Grenade Launcher it is not advised to use the Chainsaw with this weapon.
 * If possible save this weapon for the Gauntlet Crescendo event in the sewer.