Railgun Prototype

Railgun Prototype (超電磁投射砲 実験装備型) is a weapon used in the Toaru Majutsu no Index universe.

Principles
It was planned to be used in the experiment because it had a decent rate of fire, but it ended with only testing because the plan was frozen. It is a weapon that complements low-level Radio Noise.

Background
Railgun Protype was designed by Akitaka Mika from his Modern Day Mecha Musume series, which was released on 2010, three years before the release of the movie. The setting was non-canon at the time of release, but it was later introduced in Toaru Majutsu no Index Movie: Miracle of Endymion.

Toaru Majutsu no Index Movie: Miracle of Endymion
When the Sisters arrive in the Endymion to help Misaka Mikoto destroy the mobile weapons, Misaka 10032 was shown wearing a Prototype Railgun with large batteries.

Trivia

 * Akitaka Mika is the mecha designer of Railgun season 1, S, and Endymion movie and Silvercross Alpha's Powered Suits.
 * Due to popularity of Modern Day Mecha Musume, a figurine was released by Bandai.