Made by a machine. Machines never make the same thing EXACLTY the same.
Short barrels, easy to handle in close quarters. Two barrels, 2 shots fast.
Gatling gun
it depends on the manufacturer and the condition of the gun. it helps to know the caliber of all three barrels. usually you have two shotgun barrels and the third is a rifle.
The original Gatling gun had six to ten barrels which rotated and fired independently. This was one of the earliest machine guns made.
The 940 was a single shot shotgun. Sounds like it comes with 2 extra barrels. Values range from 50-100 for a complete gun. With the other two barrels, depending on condtion, you would be in the 75-175 range.
Interior or exterior?
Technically, there is no limit.
Part of the sight.
Dozens of countries
SteelSteel
Any Spyder threaded barrels.
The first ones had six barrels that used .58-caliber ammunition.