Is there any guns that start with e and what are they?

Erma EMP.35. A German submachinegun from the 1930s with a side mounted magazine.

The 'Elf' is a Ukranian-made submachinegun which fires the 9x18 Makarov cartridge, and the magazine feeds through the pistol grip in a similar manner to the Uzi.

Eagle Arms is a US firearms manufacturer, and the parent company of Armalite.

Enfield is a name commonly used to describe firearms manufactured in the United Kingdom at the Enfield Arsenal. Weapons manufactured at Enfield include the Enfield revolvers, Short Magazine Lee-Enfield rifle, the BREN light machine gun, and the Enfield EM-2. The Pattern 14 Enfield rifle was manufactured under contract for the Enfield armory.