[1][2] The intention of the combined weapon was to give infantry riflemen their own grenade launcher capability, instead of relying on crew-served mortars.
The standard S.R.2 grenade weighed around 160 grammes, with a cast-iron head, a finned aluminium tail and an explosive filling.
Grenades were impact-fuzed, with a safety ring pin removed before loading them through the muzzle, where they were then retained by a spring detent.
[3] If the bullet did jam in the trap, the fore end of the spigot was squared and could be unscrewed by a wrench in the rifle toolkit.
[iii] Also these heavier grenades, still propelled by a single rifle cartridge, had slow, high-arching trajectories needing greater elevation.
The rear sight was adjustable by the usual Carcano mechanism, but had new graduations on the side for grenade ranges of 100, 150 and 200 m.[3] The obvious drawback was the slow process of moving the bolt from one breech to the other, with the weapon unfirable in the meantime.
[4] The infantry's need for an organic mortar capacity was then met by the conventional 45 mm Brixia Model 35, introduced in 1935.