The .480 Ruger is a revolver cartridge, introduced in 2003 by Sturm, Ruger and Hornady. This was the first new cartridge introduced by Ruger, and was at time of introduction the largest diameter production revolver cartridge, at .475 inches (12 mm). It was quickly followed in 2004 by the .204 Ruger, the fastest production rifle cartridge.
475 caliber handgun cartridges are not a new idea. The .475 Linebaugh was introduced around 1988 as a custom, 5 shot Ruger Blackhawk single action revolver. The .475 is a wildcat cartridge made by cutting the .45-70 case to a length of 1.5 inches (38 mm), and necking it to accept a .475 bullet. The .475 Linebaugh is an immensely powerful cartridge, more powerful than the .454 Casull, the most powerful production revolver cartridge at the time. The .475 diameter bullet allowed bullet weights over 400 grains (26 g), a feat not possible with the .45 caliber cartridge cases, and the terminal ballistics of the heavy bullet, even when loaded to moderate velocities, were impressive. The .475 Linebaugh was designed for handgun hunting of large game, such as bear, where deep penetration is required for a quick, humane kill, and the heavy, cast Keith style semiwadcutter bullets out of the .475 Linebaugh penetrated very well.
When Ruger began to design their new cartridge, they started with the .475 Linebaugh super-magnum cartridge, but went a different direction. Rather than using the Blackhawk, Ruger chose to chamber the new round in the double action Super Redhawk, and designed the cartridge to fit in a 6 shot cylinder. The Super Redhawk was already the only 6 shot .454 Casull revolver in production, as all other makers used 5 shot cylinders to keep the cylinder walls thicker to handle the high pressures. The .480 Ruger uses lower pressures than the .454 Casull at 48,000 PSI, so the .454 Casull can still produce higher velocities and more energy. The .480 case was also shorter than the .475 Linebaugh, at 1.285 inches, the same as the .44 Magnum. The .45-70's large diameter rim is also turned down, which is required to fit the 6 cartridges in the Super Redhawk's cylinder without interference.
The .480 Ruger can be viewed as a ".475 Special", a downloaded version of the super-magnum cartridge, and in fact .480 Ruger rounds will fit and function in a .475 Linebaugh revolver, just as a .44 Special will fit and function in a .44 Magnum. Reviewing the .480's ballistics however, reveals this is somewhat misleading, as this "Special" reference, may cause one to consider the .480 as a low powered target round. In actuality, it is much closer to it's more powerful cousin, the .475 Linebaugh, than the .44 Special is to the .44 Magnum. The initial response to the .480 Ruger was mixed, as many reviewers compared it unfavorably to the more powerful .475 Linebaugh or .454 Casull, and wondered why Ruger had bothered to introduce a lower powered cartridge (this was based off of muzzle energy alone, no regard to bullet diameter or weight). Indeed, the first factory load, a 325-grain (21.1 g) bullet at 1350 ft/s, is within the reach of even the .44 Magnum. However, with bullets of 400 grains (26 g) and higher, the .480 Ruger starts to show more potential. The standard .44 Magnum powders, in similar amounts, will push a 400-grain (26 g) bullet at over 1300 ft/s. This provides 1,500 ft·lbf (2,000 J). of muzzle energy, about 50% more than commercial .44 Magnum loads, showing the .480 Ruger's good efficiency with the heavy bullets. The lower velocities and lower pressures mean the .480 Ruger has less felt recoil and muzzle blast than the higher pressure super-magnums.
The .480 is a well-balanced cartridge, providing a lot of energy without the recoil of larger hard-kicking rounds. It has been stated by many gun writers, that the .44 Magnum is typically the most powerful handgun an average person can master. The .480 should be able to take that title, as it's original Hornady loading of a 325gr JHP, easily surpasses most factory loadings for the .44 Magnum, with very similar recoil in handguns of like weight. The future of this round remains cloudy. Magazine articles and online forums were, for a brief while, replete with discussion about the potential of the cartridge. However, lackluster sales and a limited number of firearms available in this caliber have shown it to have only moderate popularity. Much of this may be due to the somewhat lackluster ballistics available from the initial Hornady factory offerings. Handloaders reported getting phenomenal performance out of the round rubbing shoulders with the .475 Linebaugh and easily equaling and even eclipsing the Taylor Knockout Value (TKO) of the .454 Casull, with less recoil, muzzle blast and noise due to the .480's lower pressures. Still, for the most part, the round was seen as not doing anything new and available loads limited its potential for the non-handloader to mere deer hunting (for which many calibers already exist to serve that need).
Also, since Smith & Wesson introduced its .500 S&W and .460 S&W Magnum cartridges, the 480 has fallen even further into obscurity as it could not compete with the glitz of these new mega-cartridges. Revolvers chambered in .460 S&W Magnum can usually accept .454 Casull and .45 Colt rounds as well (in the same way that a .475 Linebaugh revolver can take .480 Ruger), a useful cost-saving feature that can increase the appeal of the .460 over the .480 for some shooters, especially for practice sessions where full-power rounds are not necessary.