[1] At a first glance the Socimi Type 821-SMG appears to be an outright Italian copy of the Israeli Uzi, although the design sports many differences and improvements over the original project.

The firm of SOCIMI had been active in the railway building sector since the early 1970s; in 1983, it entered in a joint venture with the historic firearms manufacturer Luigi Franchi S.p.A. (which later, specifically in 1987, would have outright taken over) to concentrate on the military weapons business.

The early prototypes and evaluation samples of this sub-machinegun were shortly manufactured directly by Franchi, until SOCIMI had completed tooling-up to start in-house production.

Optimum results are obtained within a range of 150–200 metres, the telescopic bolt balances the weapon such that it can be fired one-handed with complete control.

Rumors of foreign sales can find no confirm whatsoever; before bankruptcy, SOCIMI had reached export agreements with a United States company called MTS Corporation, located in Philadelphia, Pennsylvania.