Not quite - the "Canon de Montagne de 65 Mle 1913 Saint-Chamond" used a very similar system. It seems the soft recoil system was invented by Deport but his designs were appropriated by Bacquet and Ducrest at the Puteaux Arsenal and resulted in the Schneider-Ducrest 65mm gun. An order of Saint-Chamond guns was built for export to El Salvador but the French authorities seized the guns when war was declared. The Saint-Chamond guns were given to the Belgian Army who used them in street fighting against the German Army in 1914. The Germans used captured Saint-Chamond guns in the Vosges until they ran out of 65mm ammunition.
landships.info/landshi...amond.html
Regards,
Charlie
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