Your disagreement with the Cowboy Perk, I disagree, you don't understand, its not the type of weapon, its just the weapon, Brush Gun, 78 DAM raised to 98 DAM, makes the DPS 271.
As for the shotgun perk, how is the person who stated it doing so well with shotguns already anyway? I've found all of them to be very poor at killing, and weak...
Do you use the Hunting Shotgun? and the perk And Stay Back? Is your guns skill 75 over? Is your strength high enough?
Cuz if you don't have And Stay Back then stay back from the Shotgun Surgeon (Person and Perk)
to get and stay back you have to get dead money....(assuming he has it)