We've established that the change back to mm to measure chambers from cm in Saint-Étienne occurred in 1912. We don't know exactly when. But:
-- it was definitely 1912 per dated Didier Drevet barrels
-- On the Darne number chart (Ted will caution about exceptions) it happened just around serial C600-700 (1912 per the chart):
. . . . . . .- C692, a 12 gauge with a chamber stamp "6.5".
. . . . . . .- C643, a 20 gauge with a chamber stamp "70".
Now if Berthon Frères trademarked "Canons Gallia" on 11 Jun 1912...then you've likely dated your gun to within a couple of months - summer 1912. (And incidentally we've established that the changeover to mm was after 11 June 1912).
Raimey, you and I were thinking the same thing. I suppose it's possible he was using Canons Gallia before the trademark...but....heck...lets date the gun.
David, the common idea in gun scholarship is that it's darned difficult to date a Saint-Étienne gun - there are no French dating stamps. But by chance, dating your gun doesn't get much better than this.
Last edited by Argo44; 08/23/20 08:49 PM.