The Chauchat version in U.S. .30-06 made by "Gladiator" for the A.E.F.,
the Model 1918, proved to be fundamentally defective and had to be
withdrawn from service. The weapon has a poor reputation in some quarters,
with some experts assessing it as the worst machine gun ever fielded.

The Mle 1915 Chauchat's performance on the battlefield drew decidedly
mixed reviews from the users when the war was stagnating in the mud of the
trenches in 1916. This brought about a survey, regiment by regiment,
requested by General P�tain in late 1916; the survey's essential
conclusion was that the open-sided half-moon magazines were defective and
caused about two thirds of all stoppages. For instance, it was a common
practice for the gunners to oil up the inside of the magazines to
facilitate movement of the 8mm Lebel rounds. Also, loose earth, grit, and
other particles easily entered the gun through these open-sided magazines,
an ever-present risk in the muddy environment of the trenches. An
insistence on using only good, undeformed magazines with strong springs
was the most practical solution to this problem. Chauchat gunners were
also known to load their magazines with 18 or 19 rounds, instead of the
maximum 20, in order to avoid the dreaded first-round failure to feed. The
Chauchat's long recoil system is often cited as a source of excessive
stress on the gunner when firing, though recent and extensive firing tests
have demonstrated that it is the Chauchat's ergonomics and its loose
bipod, rather than its recoil, that makes it a difficult gun to keep on
target beyond very short bursts. On most of the Gladiator-made guns, the
sights also made the Chauchat shoot systematically too low and to the
right, a failing which was soon recognized but never corrected.
Overheating during uninterrupted periods of full automatic fire (about 120
rounds with the 8mm Lebel version) often resulted in the barrel sleeve
assembly locking in the rear position due to thermal expansion, causing
stoppage of fire until the gun had cooled off. Hence, French and US Army
manuals recommended firing in short bursts or semi-auto. In 1918, the
A.E.F. officially labeled the Chauchat in its user manuals as an
"automatic rifle", a product of mistranslation of the term "Fusil
Mitrailleur", instead of "Machine Gun Rifle", a more accurate description.

Very few .30-06 Chauchats reached the front lines of northern France;
however, when they did, it was reportedly not uncommon for U.S. units to
simply discard their Chauchats in favor of M1903 Springfield rifles and
cease to function as an auto-rifle squad altogether.