The final shotgun, whatever it was called, I never liked it. The Riot gun is essentially a Benelli M3, it's perfect.The Blacktail is the best balanced pistol in the game. The fire rate and mag size can take down an army of Ganado. I only like the Handgun for the 5x critical upgrade.
I also prefer the Riot Shotgun over the other two. Higher firepower I'll take any day over mag amount.