Shotguns

12 Gauge

 * Starting ammo: 18 (upgradeable to 22)
 * Max ammo: 30
 * Clip size: 1
 * Unlock ballistic tip level: 13
 * Unlock more ammo level: 20
 * Range: 19-32
 * damage: 60-90

Double Barrel

 * Starting ammo: 24 (upgradeable to 30)
 * Max ammo: 40
 * Clip size: 2
 * Unlock level: 25
 * Unlock ballistic tip level: 32
 * Unlock more ammo level: 37
 * Range: 25-32
 * Damage: 50-80

AA-12

 * Starting ammo: 40 (upgradeable to 48)
 * Max ammo: 56
 * Clip size: 8
 * Unlock level: 37
 * Unlock ballistic tip level: 43
 * Unlock more ammo level: 48
 * Range: 16-32
 * Damage: 30-51.2

Description
Shotguns are the strongest weapons in the game, but they have little precision at long range and also have limited amounts of ammo.