IIRC, the Israeli Irgun were making homemade SMGs out of old Turkish rifle barrels, with only a dentist's drill as the sole power tool.
And I remember a scene from a documentary about the Northwestern Provinces of Pakistan, in which firearms were hand-made using hand-tools only. They looked pretty good, but I'm sure they would develop problems as the strain of firing worked upon their mechanisms.
It's amazing what a little ingenuity can produce out of "junk"--I also recall a scene from another documentary set in an Afghan town where the camera showed a device constructed out of what appeared to be flattened Glade air freshener cans--a satellite dish constructed in can metal (advertising still on) using a flower-petal overlap pattern. I guess if you can focus enough signal, you don't necessarily need a smooth collecting surface on the dish.
Thanks McGyver!
