Cu*t n Charge.
I am not sure friend. I am just being facetious.
Hopefully some of the knowledgeable American helmet guys can help.
Steve your probably right but my version would be Chief Naval Commander. It's probably not this but the only things coming up doing a military abbreviation search were Cadet Nurse Corps, Central Narcotics Center and so probably the abbreviation on the lid is something only relevant to the serviceman who wore it.
"When I lost my rifle, the Army charged me 85 dollars. That is why in the Navy the Captain goes down with the ship." -Dick Gregory-