Question: What are smaller variants of the Israeli submachine guns that copied the MCEM-2's combine wrap-around bolt and magazine in pistol grip considered to be?

<P0-S0> The Arsenal M23 submachine gun (Estonian: "Arsenali püstolkuulipilduja" ) (also known as Arsenal Tallinn) was an Estonian submachine gun from 1926 through 1935. <P0-S1>  These submachine guns were designed and produced in the Estonian military equipment factory "Arsenal" in Karjamaa, Tallinn, but production was not more than 600 units. <P0-S2>  The weapon was chambered for the 9x20 mm semi-rimmed Browning cartridge to be compatible with ammunition for the Browning FN M1903 pistol which had been adopted by the Estonian Army. <P0-S3>  It operated on the blowback system and was essentially similar to the MP18.1; having a wooden stock, slotted barrel jacket, and horizontal left side magazine feed. <P0-S4>  A uniquely slender 40 round single column box magazine led to frequent cartridge feeding problems; and cooling fins which were machined lengthwise along the barrel to promote cooling air flow when firing (similar to the Lewis machine gun), unnecessarily complicated production. <P0-S5>  It was used by the combat support units of the Border Guard, the Estonian Defence League and the Estonian Defence Forces. <P0-S6>  The Arsenal submachine gun was replaced in Estonian service by the Finnish Suomi KP/-31 submachine gun in 1938. <P0-S7>  The Estonian Army sold a few samples to Latvia and all of the remainder found their way to Republican forces during the Civil War in Spain. <SEP> <P1-S0> A weapon with a telescoping bolt (also known as an overhung bolt) is one with a bolt which telescopes over, that is, wraps around and past, the breech end of the barrel. <P1-S1>  This feature reduces the required length of a weapon such as a submachine gun significantly, and it allows rifle designs to be balanced around the pistol grip in a way that gives "pointability" similar to a pistol's. <SEP> <P2-S0> The Uzi (Hebrew: עוזי‎ , officially cased as UZI) is a family of Israeli open-bolt, blowback-operated submachine guns. Smaller variants are considered to be machine pistols. <P2-S1>  The Uzi was one of the first weapons to use a telescoping bolt design which allows the magazine to be housed in the pistol grip for a shorter weapon. <SEP> <P3-S0>  23, Israeli Uzi and a great number of other submachine guns. <P3-S1>  MCEM-2 was the second prototype in a line of experimental submachine guns, designed in Britain in 1944. <P3-S2>  It was envisioned as a possible replacement for the STEN submachine gun then in service. <P3-S3>  The MCEM-2 was developed by Jerzy Podsedkowski, a Polish constructor involved in work on Vis and Mors, who fled from occupied Poland to Britain. <P3-S4>  It is believed that prototypes of MCEM-2 were made before the end of WW2, and its derivatives MCEM-4 and MCEM-6 were tested soon after the war. <P3-S5>  The latter modifications differed mostly in adoption of the rate-reducing mechanism, incorporated into trigger unit; the rate of fire therefore was decreased from 1000 to more realistic 600 rounds per minute. <P3-S6>  Nevertheless, neither prototype was found suitable for adoption, and several years later British army adopted a more conventional submachine gun, the Sterling-Patchett. <P3-S7> MCEM-2 (Machine Carbine Experimental Model 2) submachine gun was produced only in prototype form, but was one of the very first submachine guns to combine wrap-around bolt and magazine in pistol grip, features later copied in the Czechoslovak Sa vz.