Anyone use one of these?

[handofzeus]

Found in an old ammo box. 3 tooth wrench. The hole is about a 1/4" diameter. Letter 'K' stamped on handle.

 

[kward]

its to remove the piston nut on a m1 carbine

 

[handofzeus]

Thank you! Makes sense. It came from an elderly buddy who once had one. Now I can sleep.