Unknown Russian 76.2mm case WW1 re-used WW2

[Hoeksel]

I found this Russian 76.2x250R88 case. It is originally a S.M.A. manufactured 1916 case with the text "SCHNEIDER" and LOT number 351. The primer is 1943, so I got it being a WW2 shell case collector. I know of another case with the exact same dimensions, but headstamnp unknown. It is written down as WW1 so I assume same case but with WW1 primer.

Questions:
- What does S.M.A. stand for? Is is Schneider M.. A..?
- What gun is this case for?