The shotguns are a sub-class of Assault Rifles (as they are your primary weapon if bought), shotguns are very powerful at close range but do almost nothing at long range, there are only 3 shotguns in Blackshot so far, they are:

Shotguns fire slower than other weapons in the assault rifle class, one of the shotguns, namely the Holy Shotgun, may be a fictional weapon or it may be a modified Armsel Striker Shotgun. Shotguns are best used against a group of approaching enemies, the S.P.A.S 12 and the Holy shotgun are the best shotguns to use in Bunker Defense as thier range is superior to the M3 Super 90 and they are semi-auto, only use shotguns if you need them, if not you may be wasting ammo and Bounty Points on them.