According to the information I have, what used to be called double proof is now called triple proof, with the proofmark repeated 3 times. If your gun dates from the 30's, then that's not 11,000 kilos . . . but still a very stout proof at 18,000 psi. The Robust is more or less the Stevens 311 of France in terms of numbers produced . . . but much higher quality. Very solid guns. "Robust" is a well-chosen name.
No proof house marks on that one, Larry. Manufrance was allowed to proof their own firearms at a few points in history. A few of the French guys have posted that it was equivalent to proof at the official proof house, but, I don’t know the numbers. The exact, same gun will sometimes be seen with the word “Costo” on it, instead of “Robust”. Same gun. Same manufacturer.
Best,
Ted
