Quote:
Originally Posted by sheepherder
You can have an interference fit without pressing - Heat the hole and chill the pin. Let air cool. Half a thousandth o/s pin is adequate for this.
Swaging is best done with a rotating concave tool to heat up the pin end by friction while pressing down with your arbor or press. This makes a nice rounded dome that overlaps the sides of the hole.
My vote for the Luger loop is peened in place. A special holding fixture for the frame, stick the loop in the frame and place it in the fixture, lower a ram to touch the ends of the loop (inside the frame) then whack the ram with a BMFH... 
Simple enough for slave labor and not time or machine intensive. 
I use this method for re-assembling Buck 110 and 112 folding knives after I swap blades in them...  |
Yep, a rotating swaging tool would probably be the best way to do it. From what I gather, you can even get some friction welding effects by doing that, and that would make it stick like the dickens. Like they say around here: "that ain't going nowhere!"
And just to argue with you: I just looked at some of the pictures, and looking at how smooth the frame is inside I would guess they are swaged. Staking will often leave marks deep enough to remain after you grind it flush, especially if you use the specialized gun manufacturing tool you recommend. Even a highly skilled BMFH operator would have this problem, so I'm voting for swaged.
I know that many wartime guns were simplified to cut production time and allow for unskilled labor (which, unfortunately, is the way most guns are made nowadays as well...), but I don't know if any changes like that were ever made to the Lugers. I can't recall ever seeing a "last ditch" variation, but they may be out there?