A Certain Magical Index
The following weapons were used in the anime series A Certain Magical Index:
Remington 1866 Derringer
In Accelerator's side of the Three Stories arc, Kikyou Yoshikawa uses a Remington 1866 Derringer to shoot Ao Amai after he successfully cripples Accelerator. It is lost after she and Amai shoot each other at point blank and Yoshikawa passes out.
M1911A1 is used by the varios characters during the confrontation.
In the Three Stories arc, Ao Amai uses a Beretta 92FS to defend himself as the virus he downloaded into Last Order and the Misaka network loads. When Accelerator temporarily disables Amai and deletes the virus from Last Order with his powers, Amai shoots Accelerator in the head, who cannot immediately reflect the bullet with Vector Change while busy using his power all at once, giving him brain damage.
The Sisters all seem to possess FN F2000 assault rifles for defense and combat, during and even after the Level 6 Shift experiments.
The SG 552 is seen used by Anti-Skill officers during the battle with the Golem Ellis in the Hyouka Kazekiri and Academy City Invasion arcs. Combined with its featured use in A Certain Scientific Railgun it can be presumed this is the primary firearm of Anti-Skill.
An unidentified Misaka clone uses a Barrett M82A1 to combat Accelerator at the start of the Sisters arc. It is nicknamed the "Metal Eater", for its full auto setting. Its rounds are deflected back at the Sister by Accelerator's Esper powers, destroying the weapon and injuring the Sister in the process.
M67 hand grenade
M67 hand grenade is used by Anti-Skills during the fight with Sherry's Golem.