The MP40 (MP designates Maschinenpistole) was a submachine gun developed in Nazi Germany and used extensively by Fallschirmjäger, tank crews, platoon and squad leaders and other troops during World War II.
The weapon is seen been used by many German soldiers throughout the film. In the first chapter, Colonel Hans Landa orders his soldiers to kill the Dreyfuses using MP40s. Many of the Basterds use MP40s as well, including Sgt. Donny Donowitz, PFC Smithson Utivich, PFC Omar Ulmer, PFC Gerold Hirschberg, and Oberfeldwebel Hugo Stiglitz. Wilhelm, another Oberfeldwebel, gets hold of an MP40 during the Nadine tavern gunfight. Hitler and Goebbels's opera box sentries also carry 2 MP40's, later taken by Donny and Omar.