Do not run around like a chicken with your head cut off.Shotguns are one hit kills, yes, but if you’re not good at PvP, you are going to lose those encounters far, far more often than you win them.
I would not use hand cannons, as everyone with Luna’s will outduel you at that range. They are still the best all-around primaries in Crucible, though I guess you could try some scouts after recent buffs.