Per above: 3). Saint-Etienne guns up to about 1889 appear to be chambered in mm.. So they changed to cm about 1889 and back to mm about 1912. This 1889? change is very possibly the visible evidence of the change-over from the CGS system (centimeter, gram, second) to MKS system (meter, kilogram, second) in 1889 referred to by Wildcattle. This 1889 date is as clear a date-marker as the 1912 date. Here are a few examples:
-- notice that there is a gun chambered for 75mm and one for 80mm in this group.
1). from first page: 1878 Didier-Drevet fusil (damascus) date on the gun (not the barrel). 18.6 (11 gauge); 65mm Chambers. (Date on the gun).
http://www.tircollection.com/t18880-un-beau-fusil-de-chasse-sobre-et-elegant
2). Pre-1889 Fusil Darne rotary gun (the ad claims the gun is 1892 - this can’t be since the chambers are measured in mm; -- unless of couse as Ted pointed out previously the barrels were made pre 1889 and then mated to the gun several years later). 16.8 (17 gauge); 65 mm chambers; Ronchard Cizeron barrels. (makes me want to ask that Kansas dealer, who has two of these, for photos of their barrel flats - how are they marked - in cm or mm? and who made the barrels?)
http://www.naturabuy.fr/FUSIL-DARNE-MODEL-ROTARY-1892-item-3675740.html
3). 1885-1889 Manufance under lever hammer gun; 75mm chambers; 17.4 (14 gauge). Manufance was founded in 1885; the chamber is in mm thus 1889 or earlier.
http://www.naturabuy.fr/Fusil-juxtapose-...em-3799057.html
4). Pre 1885. Saint Etienne under lever hammer gun Martinier Collin; 19.6 (8 guage - ad says 10 gauge but I think 10 gauge is 19.2); 80mm chambers; (Martinier and Collin founded the company which was sold in 1885; Their assistants then bought the company which ultimately became Manufrance.);
http://www.naturabuy.fr/rare-fusil-juxtapose-chiens-calibre-10-saint-etienne-item-2376357.html
5) 31). Pre 1889: Artisanal Saint-Etienne under lever hammer gun; 18.2; 65 mm chambered in mm. Identified as pre 1889 by the use of mm.
http://www.naturabuy.fr/Fusil-juxtapose-item-3475156.html
6). Because I mentioned two pre-1889 guns from Manufrance and Matinier-Collin above, I'll expand the story for history's sake with this gun and a translation. Chambered in cm, it is post 1889 - and since it's proofed for "PT" probably 1900-1912 - but has a relevant story to it: --
edit: Well there's an obvious problem. Blanchon was Manufrance at the time this gun was made.- i.e. chambered in cm 1889-1912 So--the "Blanchon" on this gun can't be Pierre Blanchon. More examples of the carpet merchant nature of gun dealers - wonder if his history is correct?Post 1889 Saint-Etienne under lever Blanchon: 18.2; 6.5 cm chambers;
http://www.naturabuy.fr/ANCIEN-FUSIL-BLACHON-SAINT-ETIENNE-COLLECTION--item-448377.htmlPierre Blachon arquebusier de métier à St Etienne fait la connaissance peu avant 1885 de Etienne Mimard fils d'armurier venu se perfectionner dans l'arquebuserie à St Etienne après un séjour dans le métier à Liège. Donc ils font connaissance étant tous deux employés à la Sté Martinier- Collin armurier à St Etienne. Cette société en 1885 est mise en vente et les deux hommes s'associent et achètent cette entreprise qui devient la Manufacture Française d'Armes et cycles de St Etienne, Etienne Mimard en est le Directeur général Président du Conseil d'Administration et Pierre Blachon Vice président et c'est lui qui sera le concepteur technique des premiers modèles produits par la Manufacture avec notamment l'invention du fameux Robust dont la commercialisation sera lancée en 1913 et qui en fera le fusil de chasse certainement le plus vendu au monde avec prés de 1 million d'exemplaires.
Pierre Blachon n'aura pas le temps de connaitre l'immense succès de son "Robust" puisqu'il meurt en 1914.Pierre Blanchon gun maker in St Etienne a little before 1885 met Etienne Mimard, son of a gunsmith/gun dealer who had learned the gunmaking trade in St Etienne after an apprenticeship in Liege. They both were employees at Ste Martinier-Collin, gun makers in St Etienne. In 1885 this firm was put up for sale and the two men went together to buy it, It became La Manufacture Francaise d’Armes et Cycles de St Etienne (Manufrance), Etienne Mimard becoming the Director General, President of the corporate board and Pierre Blanchon Vice President. It was he who came up with the technical conception of the first models produced by the manufacturer with notably the invention of the famous Robust, which was first launched in 1913 and which became the most sold shotgun in the world with nearly 1 million examples. Pierre Blanchon did not have time to know the huge success of his “Robust” because he died in 1914.
