After designing the bolt action rifle that bears his name, Andre Berthier went on to experiment with self-loading designs. He developed a light machine gun in the years before World War One, but was not able to interest the French government in it. He also submitted that gun for US military consideration in 1917, but was similarly rebuffed (in fairness to the militaries, the gun was not really ready for field service). Then the US issued a request for semiautomatic should rifles in 1920, Berthier and his partners at the Vickers company dated the machine gun design into a closed-bolt, semiauto shoulder rifle. After rejection at the May 1920 trials, they redesigned the gas system to be shorter, and resubmitted another rifle to the followup tests in November of 1921. That resubmitted rifle is what we are looking at today.
Internally, the rifle’s design is actually much better than its ungainly external appearance would suggest – but it was still not good enough to interest the US military. The locking system is a two-piece tilting bolt, very similar to the eventually successful Vickers-Berthier light machine gun of the mid 1920s. A firing pin is fixed to the operating rod, and the trigger releases the whole op rod to jump forward under residual mainspring pressure to fire – much like the Lewis and FG42 designs. Clever safety and manual bolt hold open levers double as takedown pins, and the whole system is really quite modern for 1920/21. Unfortunately, the rifle suffered parts breakage and its top-mounted magazine was a major mark against it in US eyes (unfortunately, the magazine itself appears to have been lost since almost immediately after the firing trials).