The John Inglis Company, to avoid expensive forging dies in making the body of the machine gun, flame-cut the blank from 2 1/8" plate steel. This blank weighed 38.5 lbs. This was reduced to 4.5 lbs on the finished part by 247 machining operations.
The process also entailed 18 inspection operations, 273 machining fixtures, 362 cutting tools and 740 gauges. And this was for only one part of the device.
The work was done for the most part on standard machine tools: grinders, drills, lathes, milling and broaching machines etc. I wonder what the percentage of rejects was.
The book is still available.