Place of origin
The .475 Linebaugh is an extremely potent rimmed revolver cartridge developed by John Linebaugh in the late 1980s. The cartridge is based on the .45-70 Government case cut down to 1.4 inches and loaded with .475-inch-diameter (12.1 mm) bullets weighing from 320 grains (21 g) to 440 grains (29 g). Although the .45 Silhouette cartridge is also derived from a .45-70 trimmed down to 1.5 inches, the .475 Linebaugh saw the same case modified to accept .475 caliber bullets, resulting in significantly different ballistic performance.
The then-new .475 Linebaugh was first announced in the May 1988 issue of Guns & Ammo in an article written by Ross Seyfried.
The .475 Linebaugh is primarily intended for hunting big game or as a backup when confronting dangerous animals. A 370-grain (24 g) bullet starting out at 1,495 feet per second (456 m/s) develops 1,840 foot-pounds force (2,490 J) of energy, and a 440-grain (29 g) bullet at 1,360 feet per second (410 m/s) develops 1,800 foot-pounds force (2,400 J). In comparison to another popular magnum revolver cartridge, the .454 Casull, the Casull's 300-grain (19 g) .454 caliber bullet at 1,650 feet per second (500 m/s) and 1,800 foot-pounds force (2,400 J) of energy is surpassed with the Linebaugh's loading of a 370-grain (24 g) .475 caliber bullet at 1,495 feet per second (456 m/s) and 1,840 foot-pounds force (2,490 J) of energy. The .475 Linebaugh and the .454 Casull are ballistically similar and both can also be loaded to higher pressures, but the .475 Linebaugh still has an edge on the latter.
As with most large magnum revolver cartridges, the .475 Linebaugh produces a significant amount of muzzle blast and felt recoil. In 2003, Ruger introduced a new cartridge called the .480 Ruger, which is essentially a shortened .475 Linebaugh that operates at 4% lower pressure, 48,000 vs. 50,000 for the Linebaugh. This results in a more comfortable shooting experience with only a minor loss in performance. Just as the .38 special cartridge will chamber and fire in revolvers chambered for the more powerful .357 magnum, the .480 Ruger will chamber and fire in revolvers chambered for the .475 Linebaugh. However, as the pressures show, the two are much closer in power than are the actual "Special" cartridges compared with their "magnum" counterparts.
The .475 Linebaugh remains a relatively obscure cartridge, no doubt owing in part to the introduction of Smith & Wesson's more powerful .460 S&W Magnum and .500 S&W Magnum cartridges, .500 S&W being the most powerful handgun cartridge in the world to date.