The SOCIMI sub-machinegun was built around a solid, monolithic rectangular receiver made out of one single piece of lightweight alloy, departing from the UZI's heavy stamped steel receiver design; the SOCIMI receiver has one single opening on the rear from which the entire bolt assembly can be extracted, while the barrel is inserted in the front and secured by a nut, and can be separated from the receiver by unscrewing it like in the UZI. The grip has finger grooves for better handling.