"Acier diamant" was not the only type of steel used by V-C. The first V-C I ever owned was an Helice 33 No. 3. V-C was kind enough to send me pages from their 1934 catalog, which was when the No. 3 was introduced. It was a higher grade gun than the Helice 33's Nos 1 & 2, which were introduced in 1933. While the No. 2 also uses acier diamant, the basic gun--Helice 33 No. 1--had barrels of "acier tres fin comprime 'Verney-Carron'". Probably some sort of cheap Belgian steel. smile