The label has not been over printed appears to be a civilian 00 buck load but front of label is clearly marked US Property. I have other US marked buck loads and the boxes are either over stamped or plain govt boxes. Thought it was a neat box. More stuff from the trove of ‘stuff’.
nice box and cartridges
I also have several other U.S. marked boxes & as you note this seems to be the only one with “U.S. PROPERTY” actually printed as part of the label design.