Lamarr Simms (Don Stroud) carries a C96 "Broomhandle" Mauser as his weapon of choice in the film, and fits the unique holster/stock combo to the back of the grip to shoulder the pistol like a rifle. Joe Kidd (Clint Eastwood) later uses it when escaping from the bounty hunters, and shows us that in Hollywood a ten shot pistol can fire about 30 rounds and lock empty several times before actually needing to be reloaded.
Canadian Ross Model 1910 (custom)
As Joe Kidd (Clint Eastwood) escapes from the bounty hunters, he grabs a rifle case containing a custom built Ross Model 1910 straight pull bolt action rifle that has been sporterized and modified as a break down rifle, and fitted with a Winchester A5 or Lyman 5A scope. The gun also has a fixed five round magazine instead of the extended ten round version. Joe uses it when battling Olin Mingo (James Wainwright) in a sniper standoff.
Remington-Keene Frontier
Olin Mingo (James Wainwright) carries a Remington-Keene Deluxe Sporter rifle fitted with a scope and with a shortened magazine tube as his sniper rifle in the film, noted by its external hammer mounted on the back of the bolt. Based on the muzzle diameter it appears to be chambered in .45-70. A similar rifle is seen used in The Sons of Katie Elder and Crossfire Trail.
Single Action Army
As with most westerns, many characters carry Single Action Army revolvers in the film, including Joe Kidd (Clint Eastwood), who carries a 7 1/2" Cavalary model. Some characters carry Single Action Armies but never draw them, such as Frank Harlan (Robert Duvall), who has one with ivory grips.
At the beginning of the film when Luis Chama (John Saxon) breaks his friends out of jail, Deputy Sheriff Calvin (Clint Ritchie) is seen using a Colt Bisley Single Action Army noted by its distinct grip shape, and fitted with pearl grips.
Savage 99
Frank Harlan (Robert Duvall) uses a Savage 99 with custom engraving as his rifle in the film. In some scenes, Roy Gannon (Paul Koslo) is seen holding it.
A Webley Bulldog with ivory grips is carried by Helen Sanchez (Stella Garcia) in the film. Possibly the same prop is also carried by Frank Harlan (Robert Duvall) in a shoulder holster.
Harry The Bartender (Ed Deemer) keeps a 10 Gauge Double Barreled Shotgun under the bar counter, which Joe Kidd (Clint Eastwood) uses to kill one of Luis Chama's (John Saxon) men when he tries to kill him. Joe later hands the shotgun to Harry at the end of the film and tells him to cover him from the bar.
One of Chama's (John Saxon) men uses an unknown revolver in the courthouse.
Table of Broken Guns
When the bounty hunters turn on Joe Kidd (Clint Eastwood), they disarm him but offer him to use one of the crappy guns seen on a table piled up. Most of them are not fireable and appear very old and rusted. They are likely actual guns of the period.