By popular internet acclaim, the Worst Gun Ever is officially the Chauchat light machine gun. Every time the question comes up, that’s what people say. I’m not saying they’re necessarily wrong – but everyone always uses the wrong photographic support material with that answer. See, there are two types of Chauchat light machine gun out there. You almost always see the standard French M1915 gun, with its distinctive half-moon magazine. That gun had a few early manufacturing problems (all resolved by the end of 1916), and was actually a decent gun crippled by terrible magazines and a hellish combat zone. The gun didn’t have a cover for the ejection port, and was susceptible to mud entering there. The mags were very fragile (if you haven’t handled one, you’ll be shocked by how flimsy they are) in addition to having big open holes for the obiquitous WWI mud. Grabbing the mag could easily dent the sides, or jam the follower in place until pressure was released. The springs weren’t very good, and effective combat units often only loaded them with 16 rounds.
All that being said, the gun itself was not too bad. Awful ergonomics, but the only real mechanical problem was the barrel heating and expanding enough to stick against the barrel shroud after firing several hundred rounds in quick succession (and overheating is an accepted issue in all air-cooled light machine guns). Take a decent condition Chauchat to the range with a good mag, and you are unlikely to have the gun give you any mechanical trouble. It may give you a good smack in the face, but that’s your own fault for not learning how to hold it properly (see also Ljungman thumb and Vickers knuckle).
The real contender for Worst Gun Ever is the US M1918 Chauchat redesigned for the .30-06 cartridge*. Development and production were rushed, and a large number of guns went out the door with incorrectly sized chambers. They were cut slightly too short, which meant that the neck of the cartridge case was jammed too tightly into the end of the chamber. Upon firing, the case would stick in the chamber and its rim ripped off by the extractor. The barrels also did not have extractor cuts in the barrel face, which didn’t help anything. They functioned so poorly that they rarely made it into combat, being exchanged for French 8mm guns before units went up to the lines (try finding a photo of the 1918 model in combat – it’s basically impossible).
So, is the M1915 CSRG Chauchat an example of great weapons design? No, not really. But it’s also not the complete failure that so many people would have you believe. I look forward to the day I can get behind one for some live firing on video, just to prove the point!
*It’s worth noting that even after WWI, a decent number of countries used the Chauchat. The Belgians came up with a fairly successful variant using the 7.65x54mm cartridge, which should settle any suggestion that the basic mechanism would be unable to handle the pressure of a straight-walled military round.