I... just don't know, never seen one before, and can't for the life of me wrap my brain around it's function.
I don't know what it is or does but I can tell you it was made by K R Wilson who made service tools for Model T's up thru the 50's Fords.
I believe it is a cleaning/adjustment tool for a m-1 garand rifle. It is missing the brush for cleaning the chamber.
Yup, that's it, a M1 Garand tool. Thanks!