Blue Thunder is a 1983 thriller directed by John Badham and stars Roy Scheider as Frank Murphy, a Los Angeles police helicopter pilot who is assigned to a top secret military weapons program that involves flying an armed superhelicopter over the city. There is a title card at the beginning of the film that states all of the technology portrayed in the film is real and currently in use in the United States military. The film would inspire two television series: a direct adaptation that aired in the US on ABC and the CBS series Airwolf.
The following weapons were used in the film Blue Thunder:
What appears to be a M61 Vulcan is the main offensive weapon of the Blue Thunder helicopter. The army weapons officer states that Vulcan's six barrels are capable of firing 4000 rounds a minute. The weapon is seen chin-mounted on a turret in the front and is able to be guided by pilot's helmet movements. A pair of Lockheed F-16As scrambled to shoot down Blue Thunder are also armed with M61s.
According to an article from American Cinematographer, the weapon seen on the flying version of Blue Thunder was actually a mockup comprised of six broomsticks painted black. For the closeups of the weapon firing, this also was a mockup consisting of six hollow barrels fitted with spark plugs to ignite bursts of acetylene blown through.
M230 Chain Gun (mockup)
Twin cannons which appear to resemble Hughes 30mm M230 Chain Guns are mounted on Col. Cochrane's Hughes 500 helicopter. Because these are only seen fired in closeup, these weapons are also likely mockups.
Handguns
Smith & Wesson Model 10 HB
Several police officers are armed with the Smith & Wesson Model 10 HB. They are seen using them when responding to the 211 at the liquor store.
Smith & Wesson Model 10 .38 Snubnose
Colonel Cochrane (Malcolm McDowell) takes out his Smith & Wesson Model 10 snubnose and fires at Murphy as he takes off with Blue Thunder. Officer Frank Murphy (Roy Scheider) points his .38 snub at an angry mechanic while he sits in Blue Thunder. Fletcher (David Sheiner) draws one as well when trying to steal the surveillance tape at the TV station.
Smith & Wesson Model 15
The Smith & Wesson Model 15 is drawn by the LA police officer (James Read) who stops Kate on the bridge. In some shots, the revolver appears to have changed into a Colt Python.
The standard police riot Remington 870 is seen being carried and fired by LA police officers.
Trivia
"Blue Thunder" in reality was a French Aerospatiale Gazelle with the cockpit canopy completely redesigned. Two such Gazelles were constructed for the feature's production. The modified helicopter would also be used in other media including the 1982 film Firefox, where the cockpit section was used as part of a Mil Mi-24 Hind; the pilot episode of the original 1985 MacGyver TV series, in the 1987 miniseries Amerika, where these helicopters were used to represent Soviet attack helicopters, and the 2011 videogame Homefront, where the helicopter was briefly incorporated in the introduction.