Steel cases (lacquered) have been produced in Italy from the last months of 1941, as the Italian Government had obtained from the Germans the possibility to buy the rights of manufacture for the process.
As long as the 6,5 mml Carcano is concerned, it can be ascertained that the rounds dated from after the date of the Italian capitulation, September 1943 were mostly made under German control in German occupied areas, both for the Republican troops and the Wehrmacht.
I also saw at Bill Woodin’s a board from POLTE-Magdeburg, with a draw set of copper-plated steel Carcano cases, but if they were probably tested, they were never adopted by the Italian Army.
We find in collections many 6,5 mm M1891 with lacquered steel cases (of course), but also some 9 mm Para, 7,82 mm Mauser, 12,7 mm Breda, 8 mm Breda, 13,2 mm Hotchkiss and also 20 mm Mauser MG 151.
Some of them, like the scarce 9 mm Para , 7,92 mm or 20 mm Mauser were probably only made in the North, under German control, but the other calibres were manufactured on both sides, from 1941-42 onwards.