First horsefly in the yogurt is there was more than one type of powder that was referred to as powder J. Second, the only truly smokeless French proof powder is powder T.
I was told on more than one occasion that, initially, the proof house had difficulty achieving proof pressure with powder T. This had not been a problem with powder S. Guns were proofed with either powder for a few years after 1900.
The laws of proof were updated in 1923. The old symbol for French triple proof, the odd marking with 4 crossed sheaths of wheat, went away, and was replaced with the 3 crossed sheaths marking. There were other significant changes as well. French proof was always high enough that I, personally, didn’t contemplate it too much from a “safe to use” aspect, as I did on my old English guns.
English guns are gone. French guns eat what I feed them, with my shoulder being the weak link, as is some consideration for old wood.
Best,
Ted
