The E-5C, a designation for the E-5C heavy blaster rifle, represented a specific type of heavy blaster rifle. Functionally, the E-5C was virtually the same as the standard E-5 blaster rifle carried by battle droids, with the exceptions of a wooden stock attachment and a redesigned barrel. During the era of the Clone Wars, the bounty hunter named C-21 Highsinger wielded an E-5C. Furthermore, Hondo Ohnaka's band of pirates, notably including Gwarm, were known to utilize this weapon. The Heavy Battle Droids of the Confederacy of Independent Systems were infamous for their deployment of these blasters, using them to unleash heavy fire upon the clone troopers serving the Galactic Republic. Occasionally, standard B1-series battle droids were furnished with the E-5C, designating them as "E-5C B1 Troopers."
Shriv Suurgav, an officer within the Alliance to Restore the Republic, employed an E-5C in the Battle of Theed.