There are several firearms throughout the mini-series that should not be there as they didn't exist at the time. Bigfoot Wallace was using a Remington model 1858 rifle, but as the model name indicates that rifle was not available until 1858, Dead Man's Walk takes place in 1842. Several people, including Captain Salazar and Gus, are seen using Colt Walker revolvers, but they were not available until 1847. See more
Long Bill Coleman
Me, I'll shoot myself in the head if I got time.
Well, that could go wrong, too. Don't be sticking no gun in your mouth unless it's a shotgun.
Why not? It's hard to miss your head with a gun in your mouth.
No, it ain't. That bullet could ricochet off a tooth... come out your ear. You'd be still healthy enough to torture for a week. You shove the butt of a gun against your eyeball... and pull. Now, that's sure. Then if some squaw comes along and chews your privates, you won't know the difference.