The only worse .30 Carbine ammo than French is Dominican Republic. I have seen many carbine barrels ruined with the French ammo, brought to us to ask why their carbines stopped functioning. Not because of rust in the bore, but because of the piston rusting to the piston housing and it getting so pitted inside that it was not salvageable. Of course, that means a new barrel in the case of the M1 Carbine.
Saw a couple of extractors blown, and in one case, part of the right locking lug, with Dominican Republic carbine ammo. Thankfully, we sold none of either. I don’t advise ever shooting either.
It is the captive piston that is the reason that the U.S. never made corrosive-primed carbine ammo from day one. The individual soldier was not authorized to ever remove the piston, although from the amount of carbine piston-nut wrenches I have seen, you would think that they were an item of individual issue (they were not).
Edited only to correct two spelling errors