The M1915 CSRG, commonly called the Chauchat after its primary designer, has a reputation as the worst gun ever put into military service. That reputation, however, is not deserved. It was not a great weapon, but it was a very serviceable gun for its day. The French needed a light automatic rifle *right now*, and needed it in large numbers. The Chauchat answered that call, and was used to great effect by many French soldiers.
The Chauchat's poor reputation comes from a couple places, some justified and some not. First off, many US troops trained on M1918 Chauchats built in .30-06, which were poorly made and pretty darn bad guns. They were replaced by 8mm Lebel guns before going into combat, but the bad experiences of training stuck with many Americans. The biggest mechanical flaw in the Chauchat was its magazine. All automatic weapons are heavily dependent on good magazines, and the Chauchat used a magazine that was made of thin metal, easily damaged, and open on the sides for dirt and mud to enter. If the magazines were not treated well, the gun would become hopelessly useless.
In addition, many of the Chauchat guns in the United States today were deactivated at one time, and often badly reactivated. This has nothing to do with their original reliability, but it does a lot to perpetuate their reputation. This particular example is an original gun that does not appear to have ever been deactivated, and it ran flawlessly for me. It will be an excellent example for someone who can appreciate it!