The 1887 Sawed-off is a cut-down lever-action shotgun built for hip-fire at point-blank range. FND Vanguards, Engineers and Special Forces Snipers carry it, and Rodolfo Claudia's insurgency rewards its unique Bases Loaded version.
Use it for clearing tight rooms and dealing with enemies who rush you. Its in-game description sums it up as a hip-fire gun, and that is how it plays best. Do not try to fight at range with it.
Bases Loaded is the reward for Rodolfo Claudia's insurgency in Los Bandidos operations. Humidora is a second named version.
It takes standard, armor-piercing, soft-target, poison, blast and incendiary shells. There is only an optic socket, so no suppressor and no laser pointer.
The full 1887 is more accurate and hits harder per shell. The sawed-off cycles faster and suits hip-fire.
1887
The 1887 is a lever-action shotgun with a seven-shell tube that you can extend to ten. It deals solid close-range damage but works the action slowly, so it rewards careful shots over panic fire.
KSG
The KSG is a semi-automatic shotgun with a 15-shell capacity, so you can keep firing in a close fight. Buy it from Juan's arms dealers, or get its unique Excavation Execution from The Long Drop treasure hunt.
M133
The M133 is a pump-action shotgun that can drop most unarmored or lightly armored soldiers in one close shot. El Rubi is its unique version, built by a Yaran furniture maker.
RMS-18
The RMS-18 is a rank 4 shotgun with a 12-shell magazine, so you can keep firing longer than with most shotguns. You can buy it or loot it from FND chests.