Did you know it took 337 gages and 94 cutting tools to make an M9 frame?
The gestation period of a Beretta M9 frame is covered in one place and with the help of 18 different receivers to show the work. The M-9 receiver production sequence is explained in 3D with actual frames in various stages of completion in an upcoming auction from Rock Island, ranging from a blank forging to a finished serialized receiver.
Starting with a 7075-T6 aluminum forging that weighs 27.7-ounces, the 65×49-inch board covers the 15 workstations and 42 machines used to cut the forging down to a 6.98-ounce completed receiver that has had 75 percent of the original material removed. Each of the stations is detailed (e.g. “Work Station #10: Mill trigger bar seat, disassembly button, right side & trigger guard area”) with the changes done to the frame highlighted in red.
There's a link to the RIA auction in the first link but I can't direct link to it from work...