GT,
all points, some good, some not, some better!
-Remember, these are the guys who made lugers from blocks of steel! A magazine would have been a piece of cake- I'm surprised they didn't just mill them from a monoblock!
-The guy that described the process, was actually, really "on the line"- I believe him, no reason to lie, no reason to make it up. He was the son of the plant or line manager or some such. He claims to have worked on the magazine line - not exactly a claim to fame!
-You really need to read the whole story, there are some 8-10 pages..
-Later on it describes the welding process which involved inserting a ceramic block for stabilization during welding of the seam.
-Post war the French(IIRC) used a yet slightly different method with an overlapping of the back and welding.
'Nuff said on that did happen or not.
Moving on to now, I thought you were pretty happy with Mec-gar mags.
They are not crimped on the sides, but where is the seam?
Have you (or anyone) communicated with Mec-gar about their process?
Would be cool to document what they decided was an "efficient, modern" process.