During the 1920s, a lot of experimental rifle development work was being done in the US. The military was interested in finding a semiautomatic rifle, and plenty of inventors were eager to get that valuable military contract. One particular item of interest to the military was the possibility of being able to convert large existing stockpiles of bolt action 1903 Springfield rifles into semiautomatics, and that is what this particular example was an attempt at.
This rifle is built with a barrel and receiver made in 1921 (it was not uncommon for the government to provide parts to inventors working in this area), and uses an operating system which is pretty much unheard of today: primer actuation. In this system, the primer pushes back out of the cartridge case (intentionally) upon firing, acting as a small piston. This pushes the firing pin backwards (as well as the bolt face in this rifle), which begins the process of unlocking and cycling. It is a system that saw some popularity for a brief time in the 20s, as it allowed semiautomatic action without the need for a drilled gas port or a moving barrel - several of John Garand's early prototypes operated this way. However, substandard performance and the need for special ammunition (most military ammunition had primers solidly crimped in place) led to its abandonment.