Making Rifle Barrels
More than 90 different operations went into manufacturing barrels for the British Lee-Enfield rifle during WWI. The first third of this booklet shows in detail how the Brits did it-- the machines, techniques, and tricks necessary to drill a long, deep, perfectly straight hole into very hard steel, straighten the tube if necessary and then cut rifling grooves.
It's heavily illustrated with photos (not great quality unfortunately), and drawings revealing the drills, reamers, laps, relieving cutters, thread millers and the multitude of other tools used.
Then it's "Drilling, Reaming and Straightening Rifle Barrels" as it was done in another factory.
Finally you get two short illustrated articles, "Machining Rifling Bars on the Bench Lathe", and "Drilling a Long Blind Hole".