7.5mm MAS

This cartridge came out of a carton marked ‘7.5mm Cartouche a balle M1929C’ which makes it a regular ball loading however I’ve not seen 7.5mm MAS ball rounds with a completely coloured primer before. Is this primer colouring of relevence?

no special meaning

Oh well…thank you anyway jeanpierre.

the primer and bullet annulus have no special meaning for 7.5 Mas
You collect 7.5 Mas ??