Today, I have the Fusil Mitrailleur Modele 1915 CRSG, otherwise known as the Chauchat. Perhaps not the best designed light machine gun and possessing some teething issues, the Chauchat is nevertheless important to the Entente's war effort by giving them the necessary firepower.
The first is the French model, the Fusil Mitrailleur Modele 1915 CRSG chambered for the 8mm Lebel.
Next is the American model, the Automatic Rifle, Model 1915 (Chauchat). Some improvements but still plagued with a flimsy magazine.
Finally the Belgian model, the FM 15/27. Pretty much the penultimate model with several design improvements such as having a whole lot of dust covers and a truly improved magazine.
And finally, the M1911 and the M1911A1. Not a Chauchat variant but they're quite well known.