This is a guide on which weapon to use over the other. We will look over which shotgun reigns supreme.
Trench Gun Edit
Main Article: Trench Gun
The Trench Gun is a shotgun dealing 20-35x8 (160-280 total) damage (Stopping Power damage is in the main article). At the range where it stops dealing one-hit kills, it will go out at a long 2-hit kill range, before becoming completely useless. The magazine capacity clocks in at 4 shells, and each shell is reloaded individually. Despite having lower damage than the DB Shotgun, it also has a slower fire rate, at 180 RPM, compared to the DB's 320 RPM. It may have a shorter one-hit kill range, but the two-hit kill range is longer than the DB's maximum effective range.
DB Shotgun Edit
Main Aritcle: DB Shotgun
The DB Shotgun deals 15-40x8 (120-320 total) damage. Unlike the Trench Gun, once the DB Shotgun stops dealing one-hit kills, which is thankfully longer than the Trench Gun's maximum one-hit kill range, it becomes worthless. The magazine capacity only has 2 shells, and is loaded as if it is loaded by magazine (2 second short, 3 second long). The Sawed Off attachment, exclusive to the DB Shotgun, increases the damage output, thus increasing range, but makes it even more useless outside its one-hit kill range (which is longer than most SMG's maximum damage range).
It all depends on your play style. If you like getting into medium range gunfights, the Trench Gun will eliminate the competition. If you are going more up close and personal, the DB Shotgun is more than worth its salt. Since they both have long reload times for their capacity, Sleight of Hand is essential for both guns. They both have worryingly small ammo reserves, so Bandolier is your best bet as your Tier 1 Perk, but if you are also getting into long range gunfights, the M1 Bazooka x2 perk is also required. The only perk tier that has no definite perks is Tier 3, but if you tend to like Molotovs for close ranges, Fireproof is needed.