Luger sub caliber device

[Lugerdoc]

Herb, Judging from the Erma E/77 Waffenamp proof on the barrel assy, it would have to be military made after 1933. If the chamber is too small to accomodate a 22lr round, it must be spoon fed, one round at a time. The mag shown is the 22lr type for the auto loading kit with their own conversion toggle assy. Tom H.