Single-action revolvers were the classic guns of the old west, and remain one of the most popular collectibles. The price of one particular gun took off like a shot at the recent auction at Butterfield & Buterfield in San Francisco, essentially thanks to one of its notorious, albeit short-term, owners, one William H. Bonney, alias Billy the Kid. The final price was $46,000.

On April 28, 1881, Mr. Bonney used this gun to shoot two guard in a successful escape attempt from the Lincoln County Jail near Carrizozo, N.M. Subsequently, says Butterfield & Butterfield arms and armor expert Greg Martin, he hid the revolver in a tree. A few months later, he was shot and killed, at the age of 21, and his friend Jesus Silva retrieved the gun.

It was bought by Robert N. Weller, a gun collector from Charlotte, N.C. Mr. Weller declined to comment. Mr. Martin says the price paid was considerably more than what the gun would have fetched were it not historically significant. Without its unique provenance, the gun would be valued at perhaps $1,200, he says.

"Colt and Winchester firearms are the blue chips of American gun-collecting," Mr. Martin says, adding that the market as a whole has seen steady "stair step" growth in recent years. Indeed, a revolver give by Samuel Colt to his nephew as a wedding present went for $2,450 in 1952. The Same gun sold at auction in 1992 for $605,000.

The buyers may be nuts about guns, but they're not dangerous. Most Collectors never fire their weapons because, as with most other collectibles, conditions determines value, and the more the gun is used, the lower its value.