Translation needed please

[Hme]

This is a German WWI mauser I came across and had Japanese Kanji on the handle. Can someone assist me please with its translation?
Much obliged!

 

[Grandpa Frank]

Although Japan & Germany were allies in WWII , this is an interesting find. Hope the translation is interesting , can't wait.

 

[Majestic]

right to left: 公為道徳
Translates to Good Morals for the Public. I don't know what the deeper meaning/context is behind that phrase, if any. Could be a slogan used during the war (although nothing shows up in a search). Lots of room for speculation.

 

[Hme]

right to left: 公為道徳
Translates to Good Morals for the Public. I don't know what the deeper meaning/context is behind that phrase, if any. Could be a slogan used during the war (although nothing shows up in a search). Lots of room for speculation.

Thank you! Will need to research more. There is a kanji Stamped on the guns barrel: