.45 acp 1917

By now even I have seen hundreds of WWI .45 ACP rounds. This one seems to have a month before the year of production. How uncommon is it?

Vlad–The government requirment that ammunition have both the month and year of production on the headstamp was dropped on 28 July, 1917, so it would appear that your 6-17 dated round was one of the last to have the month. However, I have seen “F A 10 17” rounds, so, even by the gpvernments own arsenal, the directive was not immediatly followed. Your U.S.C.Co. 6-17 are fairly common.