Goofs

When the gold wagon crashes it stops with it's right side wheels up. When Taw gets to it, it has it's left side wheels in the air.

After he opens the safe, Lomax takes a bottle of nitroglycerin and delivers it to Billy. It is completely full. When Billy begins to pour it into another bottle, it is almost empty.

During the bar fight scene, the same window is broken 3 different times by different men being punched and breaking the window as they fall through it.

From the outside of the War Wagon, the port for the Gatling gun extends to the roof of the turret. From the inside, there is a large metal panel between the top of the port and the roof.

At the beginning, as Taw Jackson scouts the movement of the gold shipment, we see a half moon in the sky. Two nights later, when Lomax rides into Emmett, there is a bright full moon. Two days later, when the "war wagon" departs on its run, we again see a half moon in the sky. Note the action of the movie takes place over only a four-day time span - too short a time for the moon to change from half, to full, to half moon again.

It is not possible so send a telegraph message by cutting the wire and reconnecting it. That would demand that the wire was powered and that the telegraph key broke the circuit rather than close the circuit. Such a device is theoretically possible but it would quickly drain the electric elements at each telegraph station and thus impractical for the period.

When Pierce fires the Gatling Gun after it is mounted on the War Wagon, it has no ammunition. The Gatling Gun's ammunition was fed from the top of the gun, either in a long magazine or a round one. Neither was in place.

The bandoleers of ammo that the guards have across their chests contain ammo that is too large to fit any of the guns (Colts revolvers, Henry repeating rifles) they are carrying.

Taw Jackson identifies the ammo offered by Wes as for a: "Gatlin' Gun". Proper names aren't contracted; and, its ammunition was standardized to the issue army .45-70 (.45 US Govt) or .50-70 cartridges in 1873, these were very common with buffalo hunters and army personnel. Their presence would raise no eyebrows.

The "gold dust" poured out by John Wayne had no gold in it. It was obviously iron pyrite. It was easily seen to have sharp edges to form particles. Gold in nature has no such angular sharp features in any natural form.

Although he is able to speak and understand Spanish throughout the movie, Taw Jackson still needs an interpreter while bargaining with Wild Horse. Given that Wild Horse doesn't want "the white man" in his camp or at his dinner table, it is reasonable that he would refuse to bargain directly with him. Also, it may be that Jackson didn't want Wild Horse to know that he spoke and understood Spanish.

As Pierce and Lomax are talking to each other, at the top left corner of the screen, you can clearly see Billy enter the bar with his empty whiskey bottle too early.

As Pierce looks out of the gun port modification to the war wagon at the adobe wall with pots on it, the magazine of the Gatling gun is seen to be empty. Also there is physically not enough room above the gun for one to fit on the gun.

When the Gatling gun is fired against the wood wall, you can see the squibs fired from the back side of the boards.

In the scene where Pierce is inspecting the war wagon, there are 2 small spots visible on the wagon not covered by black paint, revealing that the wagon is actually made of wood, not metal.

John Wayne's stunt double is obvious in long shots during the fight in the saloon.

Pierce's men carry Henry rifles, but their bandoleers hold .30-40 Krag ammunition. Henry rifle ammunition was short and blunt, not long and tapered.

Taw Jackson mentions the guards carry "Henry Rifles"; but everyone has a '92 or '94 Winchester. Henrys were obsolete in 1866.

After the gold is loaded and the gang is ready to split up right before the driverless wagon crashes you can see hands holding the reigns in the trap door under the right-hand seat.

The wagon that runs ungoverned, after the last barrel with gold falls, is driven through the opening below the seat. You can see the invisible crew driver's hands through the opening in one scene, and in the next scene when the wagon is overturning, that opening is closed again and it's not being driven.

At the end of the heist, a driver with two reins is seen through a cutout in the seat of the unguided wagon that's carrying flour and gold.

Taw Jackson and his cohorts separate the War Wagon on its run to El Paso from the mounted guards by blowing up a bridge over a canyon. There is no such canyon within 200 miles of El Paso.