Here is some excellent photo coverage of a M1919 semi build from Macleod over at the 1919A4.com boards.
I choose to drill the required holes by using the left side plate as a guide. My kit still had the lower plate attached to the left side.
When I located the holes, I only started the holes, here I am coming back to finish drilling them.
Here I used a piece of Al and a bolt to locate the last 2 holes.
I had to locate this hole. When I riveted the stop on, it fit pretty good.
Drilling the chamfers. I should have put them deeper. I had to go back after riveting and grind the heads down.
My fair (at best) riveting job.
I choose to use the weld the pin in place method for the 2 larger rivets. The 2 pins were about 3/16" shorter on both sides. So when it was welded, the 2 pins were solidly welded to both side plates. I read somewhere this was acceptable for the welding requirement for the semi project. Is this true? If not, I need to correct it.
After grinding the welds smooth.
Milling the extension down. Carbide is a must.
Widening the slot.
For the trigger return spring, I used a piece of brass and an AR 15 hammer spring. It works well.
The finished product. I still need to put the new trigger in when I get it and then refinish the gun.
For the rivets. I took a 1/2"
piece of cold roll and turned one end down so it fit into the air hammer and
turned the other end down to 3/8". I then drilled the 3/8" end with a 5/16" ball
end mill.
To install the rivets, I used an acetylene torch and heated the rivet till it
started to melt. I then used the above tool to drive the rivet home.
I also used a dremel to clean up the heads a bit. For the flat (flush) rivets, I
used the same method except the tool was flat on the end. I cleaned up all the
welds and rivets with the dremel.
