found the magazine issue!
The problems with welds reminds me of an article I read. Back in the early eighties there was a magazine on the stands called, 'Firepower'. Their bit was demonstrating DIY NFA legal conversions. One story was a guy who was building a BAR from torch cut rear, middle and front sections. He put the pieces in a jig and welded them together. Then after lights out there was a ferocious bang from the workshop. After strapping on (he was American after all) and investigating, he found one of the welds had cracked. AFter studying the problem, he realized he had pieces from WWI, WWII and Korea, and each had different metalurgy.
How this nugget stuck in my mind for over 20 years is a testament to how memories are formed, and what we remember when the story is truly interesting. (Now if I could only remember where I put my car keys?)
Sept 85, pp. 22-24, "Firepower", Turbo Publishing PO Box 15463, Santa Ana, CA 92705-0463, "One Piece at a time", by Frank W James:
''The resulting pieces were then sold to salvage dealers as scrap metal. The three pieces that made the reciever of this 1918A2 were each purchased for $50 apiece." ...
"After completion of this step, it was determined that approximately 90% of the pieces overlapped each other." ...
"The pieces were cut square,
normalized in terms of heat treating, and then welded. The holes and gaps were filled with welding material. While the welded receiver was cooling on the work bench, there was a loud
pop and it jumped into the air. A wide crack appeared in the weld between the front and the middle sections which left everyone puzzled as to the cause.
Approaching the problem from two angles, research was started in the Marine Corps archives as to the metalurgy of the Browning Automatic Rifle. Then an analysis of the leftover pieces from the bandsaw was undertaken. Both techniques revealed the same results; the front section was manufactured during World War I and the back two sections were made during World War II or the Korean conflict (sic.). How did they know? The front section had a high nickel steel content while the back sections had a high carbon steel content."
The author then described which welding rod and what heat treatment he needed to use to make the receiver workable. He ultimately finished the build and finishes the article with a range report.