Josey Wales (Clint Eastwood) carries two Colt Walker 1847 revolvers in twin holsters as his primary sidearms, although he carries four pistols in total. While not supposed to be known by the audience, the guns are converted to fire metallic cartridges instead of firing percussion cap and ball, since this it is safer to use blanks than firing blackpowder blank shot. While some of the guns are anachronistically seen with conventional metallic conversion kits with ejector rods and loading gates, these guns lack these features to try to hide its conversion. In some scenes though, the guns are non-firing models which do have percussion nipples so the audience can be tricked into thinking the guns are a percussion only. The famous image in which Wales poses with his Colt Walkers is a good example.
Colt 1860 Army
In the film, there are multiple variants of the Colt 1860 Army revolver (despite the fact there was only one available during the Civil War, since cartridge conversions didn't exist at the time), including:
Standard
The most common version of the Colt Army in the film is the standard version without an obvious conversion such as a Richards-Mason. Even so, almost all of them have a hidden cartridge conversion since it is safer to shoot metallic blank cartridges than black powder blank shot.
Loading Gate Conversion
When Wales' family is first murdered by the Red Legs, he retrieves a gun from the ashes of his house, which is a Colt Army with a cartridge conversion and a loading gate only. Due to quick camera cuts, it appears he fires far more than six shots at a time.
Richards Cartridge Conversion
Lone Watie (Chief Dan George) sneaks up on Wales and holds a Colt Army with a Richards Conversion (has a rear sight added to the breech ring instead of the rear sight on the hammer, has a frame-mounted firing pin, and a hammer modified to strike this firing pin. Also had ejector rod and loading gate) on him, boasting that only an Indian can sneak up on someone. Wales agrees and in a second, Watie has a gun to his head from Little Moonlight (Geraldine Keams).
Richards-Mason Cartridge Conversion
Colt Armies with Richards-Mason are used by several characters in the film.
Colt 1849 Pocket
Josey Wales (Clint Eastwood) carries a Colt 1849 Pocket in a breast-pocket holster, and draws it only when no other option is left.
Colt 1851 Navy
Union "Red Leg" leader Captain Terrill (Bill McKinney) carries a Colt 1851 Navy with a brass frame as his sidearm, and is notably seen using it during the slaughter of the Confederate soldiers. It is not a Griswold and Gunnison 1860 as a previous user claimed, as it has an octagonal barrel, not a round barrel like an G&G.
Rifles/Carbines
Sharps 1863 Cavalry Carbine
The Union soldiers are seen armed with Sharps 1863 Cavalry Carbines in the film.
Sharps 1865 Sniper Rifle
Josey Wales (Clint Eastwood) carries a Sharps 1865 rifle fitted with a full length J. Stevens brass tube target scope, which he uses to shoot the ferry rope in two, leaving the pursuing Redlegs stranded in the water. He later uses it to tie a white flag to when approaching the Commancheros before using it to shoot one of them off their horse.
Trapdoor Springfield 1873
Another anachronistic firearm in the film, Trapdoor Springfield 1873 rifles are used by Abe (Len Lesser) and Lige (Doug McGrath) when they attempt to capture Josey Wales (Clint Eastwood) by the river side. Later in the film, several are used by Wales' allies in the house to shoot at the Red Legs outside. In September 1865, the Allin Conversion was patented which simply converted the .58 Caliber Springfield musket to a 58 caliber breech loading rimfire, so it is plausible that the 1873s portrayed here are representative of Allin-converted rifles available directly after the Civil War.
Enfield 1853 rifles are seen in the hands of Union and Confederate soldiers, as well as used by Lone Watie and Ten Bears.
Other
Colt 1872 Gatling Gun
Union troops use two Colt 1872 Gatling Guns to mow down Josey Wales' (Clint Eastwood) comrades after they surrender, despite being an anachronistic firearm. Wales kills the gunner and loader in one of the gun carts and uses it to mow down Union troops and destroy the other gun. One of these guns was recently sold for a price of roughly $30,000 in a gun auction, in which they listed the gun as a Colt 1872 in .45-70 caliber.
Howitzer Cannon
Confederate soldiers are seen firing a Howitzer Cannon during a battle.