After being attacked by the group of assassins in the mob, Insp. Callahan (Clint Eastwood) is inspired to take out his old pistol, an AMC Auto Mag 280 chambered in .44 AMP. When his Smith & Wesson Model 29 is kicked into a curb drain by Mick (Paul Drake), he replaces it with his Auto Mag for the remainder of the film. The production crew had a very difficult time aquiring this gun to the point where they had to contact the original designer, who had enough parts in his basement to build two guns for the film. The first was left live firing so Clint Eastwood could shoot it and accurately depict recoil while the second was converted to fire blanks for the film. The gun's serial numbers were "Clint1" and "Clint2".
Colt Detective Special
Jennifer Spencer (Sondra Locke) uses a nickel plated Colt Detective Special as her weapon of choice to get revenge on the people that raped her and her sister long ago. Later in the film we see Mick (Paul Drake) use her gun to kill Police Chief Jannings (Pat Hingle).
Smith & Wesson 3000 Shotgun
Horace King (Albert Popwell, in his fourth and final role in the Dirty Harry series) uses a Smith & Wesson 3000 Shotgun with a pistol grip and a side-folding stock when showing Insp. Callahan (Clint Eastwood) his marksmanship on paper targets. Later, Mick (Paul Drake) takes this shotgun from him and uses it for the rest of the film.
Browning Hi-Power
Two of the mob assassins attempting to kill Insp. Callahan (Clint Eastwood) use Browning Hi-Power pistols. Later, Mick (Paul Drake) tries to grab his to shoot Callahan when he walks into his house unannounced.
IMI Uzi
IMI Uzi submachine guns are used by several mob assassins chasing Insp. Callahan (Clint Eastwood).
Later, we see that one of Jennifer Spencer's (Sondra Locke) victims also has this pistol.
M1911A1
An M1911A1 is used by the bank robber that Insp. Callahan (Clint Eastwood) chases when he arrives in San Paulo.
Trivia: The chase scene in the film True Lies between Harry Tasker (Arnold Schwarzenegger) and Salim Abu Azziz (Art Malik) heavily resembles the chase scene in this film and may have been inspired by it.
Another is later seen in the hands of one of Mick's (Paul Drake) men.
Remington 7600
A Remington 7600 pump action rifle is seen in the hands of Mrs. Wilburn, who points it at Insp. Callahan (Clint Eastwood) and instructs him to leave her fish market after he starts beating on her husband George (Michael Maurer).