The .475 Linebaugh
By Chuck Hawks
John Linebaugh brought forth his big .475 revolver cartridge in 1988. At that time, and for many years after, the .475 Linebaugh was a wildcat cartridge adapted to specially modified, 5-shot Ruger Bisley revolvers sold by Linebaugh. Today, however, the .475 Linebaugh has been legitimized by Hornady, who has introduced it as a factory load, and Freedom Arms, who chambers their deluxe single action Model 83 5-shot revolver for the cartridge.
While many single shot specialty pistols are chambered for rifle cartridges far more powerful than the .475 Linebaugh, Linebaugh's creation occupied the top of the heap of factory produced handgun cartridges until the 2003 introduction of the .50 S&W Magnum and the X-frame gun to shoot it.
Linebaugh created the basic .475 case by shortening a .45-70 rifle case to a length of 1.4" and turning off most of the rifle case's wide rim. The Hornady commercial version uses a straight rimmed case with a rim diameter of .540", a rim thickness of .065", a diameter of .504", and a nominal length of 1.395". The maximum cartridge overall length is 1.765" and the actual bullet diameter is .475". Large rifle primers are used due to the high operating pressure of the cartridge.
The loads developed by John Linebaugh for the .475 include a 325 grain LBT cast bullet at a muzzle velocity (MV) of 1700 fps, a 350 grain LBT cast bullet at a MV of 1600 fps, a 400 grain LBT cast bullet at a MV of 1500 fps, and a 425 grain LBT cast bullet at a MV of 1400 fps from a 7.5" barrel. Linebaugh says these loads do not exceed a maximum pressure of (gulp!) 50,000 psi. These loads are not thumb busters, they are wrist busters!
Note that hard cast bullets penetrate deeply, but expand little if at all. And the leading must be removed from the barrel or accuracy is degraded.
The Hornady factory load uses a 400 grain XTP-Mag bullet at a MV of 1300 fps and ME of 1501 ft. lbs. The figures at 50 yards are 1179 fps and 1235 ft. lbs., and at 100 yards the velocity is 1093 fps and the remaining energy 1060 ft. lbs. The .475 Linebaugh hits harder at 100 yards than a .44 Magnum does at the muzzle.
The Hornady 400 grain XTP-Mag bullet was developed for the .475 Linebaugh cartridge and is supposed to provide adequate penetration and good expansion for maximum killing power. It has a ballistic coefficient of .162 and a sectional density of .253. The latter is high for a pistol bullet and definitely shows the potential for good penetration.
According to the fifth edition of the Hornady Handbook of Cartridge Reloading the reloader can achieve a MV of 1100 fps with 21.1 grains of Winchester 296 powder behind their 400 grain XTP-Mag bullet, and a MV of 1350 fps with 26.0 grains of 296 behind the same bullet. The ME of the latter load is 1618 ft. lbs. At 100 yards the velocity is still 1114 fps, and the energy is 1164 ft. lbs. That is enough power to take large game at normal handgun ranges, as long as the shooter can get the bullet into a vital spot.
The trajectory of the 400 grain XTP-Mag bullet at a MV of 1300 fps looks like this: +1.7" at 25 yards, +2.7" at 50 yards, +2.2" at 75 yards, 0 at 100 yards, and -10.1" at 150 yards (Hornady figures). This trajectory should allow for solid hits in the heart/lung area of deer size game with a center hold out to about 125 yards, if the shooter can hold that well. (Unfortunately, very few can, especially with a powerhouse like the .475 Linebaugh.)
Recoil, of course, is always the problem when shooting heavy bullets at high velocity. According to the "Handgun Recoil Table," shooting a 400 grain bullet at a MV of 1300 fps in a 3.2 pound revolver (like a Freedom Arms Model 83) produces 38.1 ft. lbs. of recoil energy. This is far more kick than most shooters can stand from a rifle, let alone a handgun. The shooter attempting to master a .475 revolver should have a very strong grip, considerable forearm strength and understand proper shooting positions.
The muzzle blast is terrific, so always wear maximum hearing protection, even when hunting. This is not an easy caliber to shoot, and anyone considering the purchase of a .475 Linebaugh revolver should insist on firing a few groups at the range before they seal the deal.
To close I can do no better than to quote john Linebaugh himself, from Linebaugh Custom Sixguns promotional material: "The .475 is a true big bore that offers real big bore punch and high velocity in a practical, packable, package. This is a fairly violent round, and recoil is heavy and very sharp with top end loads."
Copyright 2003, 2012 by Chuck Hawks. All rights reserved.