What kind of french gun? Recoilless?

[Gran Sasso]

Any ideas?

[type91]

It looks like a M1916 37mm gun as used by the Americans during the very early stages of WW2 As well as WW1 and by the French.

[Dresden]

It is a French 37 mm Trench Gun, model 1917, US Steel made them for the American Army as well, most were destroyed after the war as there was a fear revolutionary communists would get them, the breech is the same as on the French 75, the gun also had a scope sight. The shells were short, projectiles were small, but effective, anti-tank use was not considered.