Tactical Shotgun and Assault Shotgun both don't require pumping.
Tactical Shotgun deals slightly more damage then Assault Shotgun, but has 1 less shell capacity.
Which one is better?(Especially for Shottyheads)
Edit: I also wish to know which of these shotguns should I make nano shrapnel(super shotgun not available yet, would be the obvious choice though):
Tactical Shotgun
Assault Shotgun
Regular Shotgun
Plasma Shotgun
Combat Shotgun
Double Shotgun(I wouldn't recommend this for long range)