Old draw bore pegs that are removed exhibit parallel deformation over the span of the tenon though whether this happens straight away or over prolongued periods of time is difficult to say.
Ken,
This happens fairly quickly as we have removed pegs from a frame we built only a few months earlier and the pegs had the parallel deformation, or as Tim mentioned the tenon impression, just like pegs I have seen that are 150+ yrs old. It was interesting to dissassemble some of our work.
