Brimstone

With all the honest men fighting the Civil War, the desperate mining
investors put together a collection of outlaws, killers, and thieves to re-take
Brimstone - by any means necessary! Led by "The Viper," a brooding
gunslinger whose brutal exploits are the stuff of Western legend, the vicious
posse finds the bullet-ridden town littered with dismembered corpses, but its
gold stores untouched. In Brimstone, the most feared men in the West have
finally found the very heart of fear!