Larry,
You forget that both the powders and proofing were done by government agencies. They all used "poudre pyroxylee" as opposed to "nitro" (which has never been used in French unlike in English) or "sans fumee" or..., so there it is, the official wording. There is a strong possibility (for which I don't have a proof yet)that it is the source of the P in PS, PT etc.
My French Dictionary shows the definition of "pyroxyle" as :
"product resulting from the action of nitric acid on a substance containing cellulose (wood, paper, etc..)", which is of course the same as NitroCellulose in English.
By the way, if you read the gun description in GB, it does show that the gun is engraved with "Poudre Pyroxylee".
As for the Belgians, they are well... Belgians, and are therefore untitled to be different.
You might recall that a screw is called a pin in England. Same story.
Best regards,
WC
