Making a Southgate Ejector Tumbler

This BLE came in with a broken left-side ejector tumbler so a new part needed to be made.  While the Southgate ejector is very simple in operation, the tumblers are among the most complex of the internal parts to make and fit.  The process is detailed below.

The original part failed at a thin section that was where a sharp inside corner was left.

I selected an appropriately sized piece of  W-1 stock and went to work.  At this point the milling machine work was done and the part would be finished by hand with files.

The part rough shaped...

The finished part, notice the generous inside radius at the point where the original part failed.

The inboard web was also made thicker than the original part to add some strength in this highly stressed area.

The tumbler was heat-treated and polished before installation then fitted so that its timing was perfectly matched to the right ejector.
Total time 7 hours.