Ron and Wes,
A very interesting discussion which does not ease my mind. Applied to the clear speculations, Occam's Razor would seem to cut closer to the steel torsion memory idea.
The only concrete thing I have to offer at the moment is the witness mark on a 1900AE, to my eyes clearly and unequivocally struck with a single blow of a sharp tool after the barrel and receiver were assembled.
--Dwight
