Haenel Magazine 16/20 round

[Germanpistolman]

Does any collector in the LugerForum recognize this illustrated magazine in the photographs which was recently unearthed in Germany.

It has not been confirmed if it is a 16 or 20 round magazine. But it has what we believe to be the Haenel 122 number marked a the bottom of the tube. Is it possible that this could have been a prototype or what? The Wood bottom is angled and is not known if it is original to the mag or not.