(Judging from the size of the bore in the images below, this looks more like a Smith and Wesson
Model 25 .45 Colt standing in for a Model 29 .44 Magnum. Most likely this was done to allow for
the use of 5-in-1 blanks, which would be easier to acquire than .44 Magnum blanks.)
After being attacked by the group of assassins in the mob, Insp. Callahan (Clint Eastwood) is inspired to take out his old pistol, an AMP Auto Mag Model 180 chambered in .44 AMP. When his Smith & Wesson Model 29 is kicked off of a dock 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 in live firing mode 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".
Jennifer Spencer (Sondra Locke) uses a nickel plated 3rd Generation 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). The barrel diameter indicates that it is a .44 special instead of a .38 special.
(This is actually a .38 Special and not a .44 Special. The Colt Detective Special was never chambered for the .44 Special cartridge; the frame size of the gun is too small. The barrel diameter does indeed look large in the picture where Sondra Locke is holding the gun, but this is because she is a petite female. Note how the gun looks smaller in the picture where Paul Drake holds it.
but what about the fact that the first picture of the gun itself says, "Detective Spec.-.44 Special"? Look closely.
The gun pic is a little blurry but if you use the Microsoft magnifier application
you can see that the gun barrel says "Detective Spec" on the first line and ".38 Special Ctg" on the second line.
This is a great page and apart from this all the other gun info looks accurate to me. The pics are all great as well.)
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 after he stabs him and uses it for the rest of the film.
Two of the mob assassins attempting to kill Insp. Callahan (Clint Eastwood) use Browning Hi-Power pistols. Further on in the film, another mob assassin tries to kill Callahan in his apartment in San Paulo, also with a Browning Hi-Power (This one fitted with a suppressor), but trips on Callahan's dog Meathead, giving him time to draw his Smith & Wesson Model 29 and kill him. Later, Mick (Paul Drake) tries to grab his own Hi-Power to shoot Callahan when he walks into his house unannounced.
One of the robbers during the diner robbery is seen using an Ithaca 37 shotgun before being killed. One of the police officers that soon responds to the robbery is also seen using an Ithaca.
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.
A Remington 7600 pump action rifle is seen in the hands of Mrs. Wilburn, who points it at Insp. Callahan (Clint Eastwood), though she doesn't fire it, and instructs him to leave her fish market after he starts beating her brother George (Michael Maurer).
Ray Parkins (Audrie J. Neenan) shows off her personal protection, a Beretta 92SB tucked in her waist "Mexican carry" style to Tyrone (Wendall Wellman) in his hardware store. It is assumed to be the 92SB because the earlier Beretta 92 variants had a butt-mounted magazine release and the Beretta 92F didn't exist yet, leaving only the 92SB.
San Paulo patrolman, Officer Bennett (Mark Keyloun) tries to fire his Colt Trooper at the bank robber but is injured before he can fire off a shot. Later, one of Mick's (Paul Drake) thugs is seen shot in the head by Insp. Callahan (Clint Eastwood) while holding a Colt Trooper belonging to Horace King (Albert Popwell) from his holster.
The jocks who are insulted by Insp. Callahan (Clint Eastwood) in the elevator try to burn his car with Molotov Cocktails, one of which burns the back of his car while the other one fails to shatter. Callahan then parks his car over and uses the unbroken Molotov to burn their car and causes them to crash into the river.
