Herstellung der Minenwerfer und ihrer Munition

Part 2: Manufacturing of Mortar Barrels
Image: Preheating the steel block in the melting furnace; Preliminary forging of the heated block under the steam hammer; Removing the block ends; Forging of the lower tube edge in the forging press; Boring of the barrel; Extracting the remaining core by wedges, milling of the rifling. (Fragment)

Source: Bundesarchiv