WWII USA M18 Case Stencilling

[hicky1300]

Hi all
Found a few cases at yesrterdays Waterloo market.
One that interested me was a 1943 dated M18 75mm cases.
Apart from still having a lot of the usual stencilling on the head as well as the usual headstamp info it had `SUPER` stencilled across the head & down one side.
I know that the French/Belgians used to put a black cross on the head of cases to denote a more powerfull propellant load/charge.
Does `super` mean the same for US cases/loads? Or did someone just think this case was special?!! :tinysmile_fatgrin_t
Apologies for no pic but horrid weather & the guy wanted a lot of money so couldn`t be bothered!!
Thanks in advance

 

[HAZORD]

There were multiple uses of 75mm guns by the U.S. in WWII, Tank, Antitank, and Aircraft, but all the guns had the same chamber dimensions. There were 3 charge loadings for the cartridges, Reduced, Normal, and Supercharge. Yours is a Supercharge case. In addition, rounds for the Aircraft guns had an additional chemical added to make them flashless, and the cases were also marked "Flashless".