Chris,
To make the rivets I first turn a piece of brass stock to the dia, of the rivet head, then turn it to .002" smaller than the dia. of the hole in the outer most part to be riveted to the length of the width of both parts to be riveted plus .015".
Next I turn the rivet to the dia. of the hole in the innermost part (.005 less than the outer part) to the length of its width plus .010".
I then use a centering drill to drill into the end of the rivet that will be crimped (about .005").
The rivet is then parted from the brass stock .020" from the end of the second cut .
Now the hard part, finding the rivet that just went flying as it is cut off.
Having photos would probably help the explanation.