Chambered for 2 3/4". Not sure the meaning of "L'epervier" as a gun term. ('L'epervier" appears on a number of nautrabuy.fr guns. Several posters claims it is a model of a Fanget barrel.
Cette canonerie portait le sigle "épervier " qui est le modêle et la marque déposée de la maison FANGET Canons en 1950 .The name Pierre Dechelle has appeared here before:
https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=497422&page=5Here is what I wrote at that time:
Pierre Dechelle. There are several guns with barrels with his name from the late 40's-60's on
www.naturabuy.fr. Can't find a lot of history. There is some backing and forthing on Passionlachasse.com with mention of his name. Here is a little clip from an article I can't get total access to:
Rough translation:
in the 40's the Barrel maker Jean Breuil took on the services of a well known barrel maker Francois Deschelles, who had begun with the Manufacture National d'Armes. In 1946 Deschelles took over the barrel maker at Rue des Francs-Macons in Saint Etienne. With his partner Paul Terrier he developed the honing of barrels in 1951 and adopted the stamp Pierre Dechelle and not Deschelle, which creates confusion.
Paul Terrier apparently in the 1970's opened a gun repair shop in Saint Etienne (same shop referred to on passionlachass.fr..).
www.canonnerie-stephanoise.fr/Here is a Fanget barrel with "Pierrage Dechelle".
https://www.chassepassion.net/forums-chasse/topic/information-sur-un-fusil-de-famille/According to Passion La chaise poster, "Le Pierrage" was the internal finishing of the barrel. The fact that the name of the finisher was placed on the gun was an indication of the quality of the work. (edit: word turned out to already be in our Fr-Eng, Eng-Fr dictionary).
So it looks like you know what firm made the gun, what company made the barrels and the model, and who reamed and honed the barrels. That seems a pretty complete history.