A Certain Scientific RailgunA Certain Scientific Railgun - Internet Movie Firearms Database - Guns in Movies, TV and Video GamesA Certain Scientific Railgun
The current leader of the Big Spider gang, Tsuguo Hebitani, carries a Smith & Wesson Model 29, which he loves to wave around and threaten his own people with, especially if they question his claim to being Wataru Kurozuma, who was in fact Big Spider's previous leader.
Aside from Tsuguo Hebitani's Model 29, all firearms used by Big Spider are M1911s. Although they love to threaten people with them, they aren't the type to actually kill people, as the gang did not start out as violent as it has become under Hebitani's rule. As such, most of them are too hesitant to actually open fire with them. The hammers are never depicted as cocked (a requirement to fire an M1911), though as they're never fired it's a bit of a non-issue.
Anti-Skill, Academy City's SWAT-style security agency, uses SIG SG 552s fitted with Aimpoint CompM2 sights and flashlights as their standard issue rifle. The SG 552s' handguards are notably longer than the real one, closer to an SG 551, though this is a consistently depicted feature and seems to be an intentional artistic liberty.
Multi Active Rescue helicopters are armed with chin-mounted GE M134 Miniguns, though how a rescue service could possibly justify this is anyone's guess.
