Hard Hit Heart

We are curious what "HARD HIT HEART" indicates on the Mauser Model 98 Germany Conversion 12 gauge Bolt Action Shotgun below. This gun is from Zane Wilson's Collection.

Our research indicates that Germany was not allowed to build military caliber weapons after World War I as a result of the Armistice. Since Germany had many Mauser 98 actions remaining unused, they converted some of these to shotguns in the 1920s for export. This particular one has "HARD HIT HEART" stamped on the stock and the bolt disassembly hole in the stock is replaced by a carving of a heart.