The Winchester Model 1897, more commonly referred to as the Trench Gun or simply the M1897 is a pump-action Shotgun designed by John Moses Browning. It is an improvement to the Winchester Model 1893. The weapon was popular among American soldiers during World War I, and at one point was even protested by Germans over its usage.
— In-game description
It possesses an unusually high rate of fire for a shotgun thanks to its ability to be slamfired; if the player continues to hold downas with an automatic weapon, the M97 will fire as soon as the pump is completed. However, firing as fast as possible causes significant accuracy loss, making it only advisable to do so at very close range.
Four variants of the M97 Trench gun are available to the Assault kit in multiplayer: Backbored, Hunter, Sweeper, and Hellfighter.
The Backbored variant of the weapon decreases the weapon's recoil but increases the weapon's damage falloff, essentially making follow-up shots easier to hit at the cost of increasing the likelihood the user will have to make one. As it features no visible choke modification, it can be considered the base variant.
The Hunter variant adds a tight choke that decreases the weapon's spread and damage falloff, making it better at medium-range, at the cost of ease-of-use in extreme close-quarters.
The Sweeper variant adds a wide choke that increases the weapon's spread and pellet count, making it better at fighting in extreme close-quarters at the cost of range.
The Hellfighter variant is exclusive to owners of the Hellfighter Pack. It's essentially the Backbored variant, but is equipped with an exclusive Hellfighter-themed skin.