It was derived from a small arms development program that took place between 1918 and 1922 under the control of the Service Technique de l'Armement.

Budgetary pressures resulting from the building of the Maginot Line led to the delay of adoption of these new arms except for the LMG 1924.

The 7.65 French Longue cartridge is nearly identical to its predecessor used by the Pedersen device, but with slight differences in the groove of the shell.

This was also the cartridge used for France's M1935 series of service pistols, allowing for limited standardization, but with the effect of preventing French soldiers from using captured enemy ammunition.

This is because the receiver and butt diverge in alignment from the axis of the barrel by several degrees, making the weapon compact as its bolt recoils inside a tube running through the buttstock, while also enabling a lighter bolt to be used by providing mechanical disadvantage to the pressure from the expanding propellant gases.

The odd appearance of the MAS-38 did not detract from its accuracy, but its cartridge was underpowered compared to the German 9mm standard pistol ammunition.