Originally Posted By: ninepointer
Can anyone elaborate on how the tubes are made? The video shows the machining, but are they first forged on a mandrel?


Shotgun and rifle barrels start from this. They're drilled, bored, rifled (if a rifle) and contoured externally before being joined and ribbed.

This is the breech end. The extra material projecting below the "tube" will become the barrel lumps.

The second photo shows the tube portion in a rough turned state.