The Ruger Hawkeye Pistol

Ruger has been using the Hawkeye name lately for a series of bolt action rifles, but the original Ruger Hawkeye was a single shot pistol it built for a brief time in the 1960s. It was built on the classic Blackhawk frame, but instead of a cylinder it had a revolving breechblock:

The Hawkeye was offered in only one chambering- .256 Winchester Magnum, which was a .357 Magnum case necked down to accept a .257 caliber bullet. The .256 Winchester was created for the Hawkeye, and was winchester's response to the .22 Remington jet, which was also built on a necked down .357 Magnum case and was offered in the S&W Model 53 revolver. Both were designed as varmint cartridges, and while both have their following, neither was a huge seller.

While the two cartridges have have very similar ballistics, they have a sharply different appearance. The  .256 looks like the typical bottleneck cartridge, while the .22 Jet has a gradually sloping body that tapers over almost the full length of its case. That turned out to be the Achilles heel of the .22 Jet. Unless cylinders and cartridges cases were kept very dry and clean of oil, on firing the Jet case would be forced rearward and lock up the cylinder. In most revolvers, the expansion of the case on firing allows the case to grip the cylinder walls, even when there's some oil there, but the tapered form of the Jet meant the the expanding case exerted even more rearward force.




The bottleneck design of the .256 meant that setback was not a problem, and the swinging breechblock design all but eliminated any chance of jamming. Problem was, not that many shooters saw the need for a flat-shooting .22-.25 caliber varmint pistol.
Those who were looking for such a gun typically bought a Thompson/Center Contender single shot, which came out in 1967. The Contender had a more solid lockup than either the Hawkeye or the Model 53, and could be had in just about any caliber imaginable via interchangeable barrels.

The Hawkeye is another curious pistol I'd like to add to my collection, but it's not likely that's going to happen any time soon.  Only one short production run of guns was made, and the last one I saw for sale on Gun Trader was listed at $3,800.