Ted, I would beg to differ.
The French equivalent to Nitro is "Poudre Pyroxylee".
My 1900 "Manufacture francaise d'armes de St Etienne" clearly puts the J, S, R, T, M & BN powders in that category.
The 1910 catalog also says that the S powder produces the highest pressure and therefore all R models are proofed with it.
The Proof mark is Crown over P.X. (X=J, S, T, etc.) for the Nitro powders and crown over F or S for the black powder guns, S being superior proof. Are you confused yet?
The "R" addendum disappeared in 1925 simply because almost nobody used exclusively Black powder at that point, and therefore, every gun was really an R.
The GB gun is one of 2008 built in 1900 (source:Mournetas).
As far as the chokes, standard French chokes are 1/2 and Full.
If anybody knows of an Ideal double rifle (they were made in a bunch of calibers from .303 to 450NE), please let me know!
Happy New Year!
WC-
