The Chauchat may have been the best light machine gun of its time by virtue of being the only one, but I wouldn't call it a success. Due to dirt and mud entering the action, mostly through the open sided mags, and difficulties caused by the 8mm Lebel cartridge, it was a problem child that a lot of our guys tossed aside the first chance they had to get something else, like a bolt-action rifle. If it was really that good of a gun they wouldn't have cursed at them so bad and thrown them away like trash.
And I don't know what undeclared wars we've fought against who over the last 200+ years. They didn't teach us that kind of stuff in school and I don't read history for fun. I don't know very much about all the wars that actually were declared. I only remember having 1 semester of history in high school and it was called Wars of the 20th Century. When I didn't need credits in any particular subject to graduate I chose classes I like, wood shop, metal shop, and art for example, and easy stuff like algebra, geometry, and science classes. Not boring old history or English classes.