It looked OK.  Packed in ordinary tan-colored pasteboard 20-round boxes.  FA headstamps from the late 1920s.  Spitzer bullets, the kind of flat base match bullets used in the 30-06 before the 172-grain boattails. 

A Chief told me that the ammo was for the M-1903A2 sub-caliber device.  Those were used in some WW-2 and earlier guns used by the USMC and apparently in some of the Navy's 3-inch & 5-inch guns. 

I probably could have appropriated some, but I was afraid to shoot it.  I had a 96 (probably Bannerman) sporter (still have it) but I thought the loads might have been too hot.

A couple of years ago, I got a copy of Brophy's book and read about Krags used as sub-caliber devices.   Could a Chief be wrong?  Brophy also wrote that the M2 Springfield (22 Long Rifle) barreled action was used as a sub-caliber device.  Now I'm confused. I have never seen a device, only the printing on ammo boxes.

About then, I also learned that the Krag sub-caliber ammunition was loaded to a MV of about 1960 fps.  That stuff would have worked safely in a Krag but the loaded rounds were too long to function through the magazine.