Left 4 Dead 2/Weapons

Pistol
The regular pistol, with a new skin, from the original Left 4 Dead. This can be dual wielded if a second pistol is found. If you trade your two pistols for a melee weapon or a magnum, you will only be able to trade back for a single pistol.
 * Magazine capacity: 15

When dual wielding you will be able to fire 30 rounds instead of 15.

Magnum
The magnum has a smaller magazine capacity, but deals more damage. Like the regular pistol, the magnum also has unlimited ammo. Its speed is usually a factor when deciding between two regular pistols or a melee weapon.
 * Magazine capacity: 8

AK-47

 * Magazine capacity: 40
 * Total ammo capacity: 400 (360 + 40)

M4A1

 * Magazine capacity: 50
 * Total ammo capacity: 410 (360 + 50)

AK ??

 * Magazine capacity: 60
 * Total ammo capacity: 420 (360 + 60)

Automatic

 * Magazine capacity: 30
 * Total ammo capacity: 150 (120 + 30)

Grenade launcher

 * Magazine capacity: 1
 * Total ammo capacity: 31 (30 + 1)