The .458 Caliber Family (.45-70, .450 Marlin, .450 NE, .458 Win. Mag., .450 Rigby, .458 Lott, .460 Wby. Mag.)
By Chuck Hawks
.458 bullets in the 350-500 grain weight range seem to have just about the ideal balance of cross-sectional area and sectional density (SD) for hunting dangerous game. Use 350-450 grain bullets for the largest predators and 465-500 grain bullets for thick-skinned game. The SD of a 400 grain bullet is .272 (nearly identical a 180 grain .308 bullet) and the SD of a 500 grain bullet is .341, which is truly outstanding and well beyond the .300 SD recommended as the minimum for thick-skinned game. (For example, the 300 grain .375 bullet has a .305 SD.)
There probably would have been no need for odd calibers beyond .458, such as .500/.465 NE and .470 NE, had the British government not made all .45 caliber rifles illegal for civilians in their Sudan and Indian colonies in 1905, when insurgents were rebelling in both places and using captured British .577/.450 rifles against the Redcoats.
At that time the .450 3-1/4" Nitro Express was the most popular of the British dangerous game cartridges, with thousands of hunting rifles so chambered in use in sub-Saharan Africa and the Indian sub-continent. Introduced in 1898 by John Rigby & Company and based on the earlier .450 3-1/4" Black Powder Express, the .450 3-1/4" NE was an immediate commercial success and .450 NE double-barreled rifles were offered by many manufacturers in the UK and Europe.
The .450 NE uses a rimmed, straight tapered case 3.25" long. The rim diameter is .624" and the head diameter is .545". The bullet diameter is .458" and the maximum cartridge overall length (COL) is 3.95". According to A-Square, the MAP is 39,187 CUP. This huge cartridge is too big for repeating rifles, but fine for single shots and doubles.
The original load used a 480 grain bullet (SD .327) at a muzzle velocity of 2150 fps and muzzle energy (ME) of 4930 ft. lbs. These ballistics proved to be ideal for the African Big Five dangerous game animals, as well as for tiger and water buffalo in India and Southeast Asia. Most subsequent .458-.475 caliber dangerous game cartridges have been designed to approximately duplicate the ballistics of the .450 NE.
After the British outlawed .45 caliber sporting cartridges the popularity of the .450 NE suffered, but because there were so many .450 rifles already in existence the caliber did not completely disappear. After WW II, with the .45 caliber ban long irrelevant and forgotten, new .458 caliber cartridges were introduced and the .450 NE itself experienced a revival. A-Square, Hornady and Kynoch now offer factory loaded ammunition using 465-500 grain solid and expanding bullets with ballistics similar to the original load.
The most successful post-WW II cartridge designed to duplicate .450 NE ballistics in a format suitable for most bolt action rifles is the .458 Winchester Magnum. Introduced in 1956 in the Winchester Model 70 African rifle, the .458 Win. Mag. was the first American big bore cartridge designed for African dangerous game hunting.
Based on a shortened, blown-out, straight taper, .375 H&H Belted Magnum case, the .458 Winchester is designed for magazine rifles with standard (.30-06) length actions. This makes it adaptable to practically all mass produced, bolt action hunting rifles.
Since its introduction in 1956, there have undoubtedly been more .458 Win. Mag. rifles built than for any other .45 caliber dangerous game cartridge. Browning, Winchester, Remington, Ruger, CZ and many others have chambered for the cartridge.
The .458 Win. Mag. case is 2.50" long and uses the standard belted magnum .532" rim diameter. The case head diameter is .5126" just forward of the belt and .4811" at the case mouth. The maximum COL is 3.34" and the bullet diameter is .458". The SAAMI maximum average pressure (MAP) limit is 53,000 CUP.
The original Winchester factory ballistics called for a 500 grain bullet at 2130 fps MV and 5040 ft. lbs. ME from a 26" barrel. This required a compressed load of Winchester ball powder and it was eventually discovered that sometimes the powder in older cartridges clumped, making for unreliable performance. Winchester long ago changed to temperature resistant, non-clumping powder and solved the problem, but to this day the old rumors about unreliable performance persist in some quarters.
Most modern bolt action safari rifles come with 22-24" barrels and the current SAAMI test barrel length for almost all rifle cartridges, including the .458 Magnum, is 24". A-Square, Nosler, Winchester, Federal, Hornady, Norma and others offer .458 Win. factory loads. Current US factory load ballistics call for muzzle velocities between 2010 fps (Winchester) to 2140 fps (Hornady) with a 500 grain bullet.
Because it uses a shorter, more modern case than most of its competition, the .458 Win. Mag. is a flexible cartridge for which to reload. It is probably the most versatile of the .458 African cartridges.
Most bullet makers offer .458 projectiles ranging from 300 grain JHPs intended for use on Class 2 game to 500 grain solids capable of punching through an elephant's skull. This allows handloaders to produce moderate recoil reloads using 300 grain bullets that duplicate .45-70 ballistics, all the way up to full power 500 grain elephant loads.
Medium power loads using controlled expansion bullets weighing around 400 grains at about 2100 fps kick less than elephant loads and are more than adequate for the largest North American dangerous game. For this reason, Winchester's .458 has found favor with some Alaskan guides to protect clients hunting Kodiak and brown bear.
The .458 Lott was originally a wildcat cartridge designed by Jack Lott around 1971. It was standardized by SAAMI to A-Square specifications in 1998 and has become the biggest challenger to the popularity of the .458 Wincher Magnum.
The .458 Lott is based on a full length, blown-out, straight taper version of the .375 H&H Belted Magnum case necked-up to accept .458" diameter bullets. The rim and belt diameter is .532" and the head diameter is .513" directly in front of the belt. The neck diameter is .481", the maximum case length is 2.80" and the maximum COL is 3.60". The MAP is 53,701 CUP. Since it is essentially a longer version of the .458 Winchester Magnum, .458 Win. Mag. cartridges can safely be fired in .458 Lott rifles, but not the reverse.
Typical ballistics call for a 500 grain bullet at a MV of 2300 fps and ME of 5873 ft. lbs. from a 24" barrel. Factory loaded ammunition is offered by Hornady, Federal, A-Square, Nosler and possibly others. Needless to say, with this much power, the .458 Lott has proven a very reliable stopper on the African Big Five.
The .458 Lott requires a long magnum (.375 H&H length) rifle action. Ruger, CZ, Kimber, Nosler, A-Square, Blaser and others build rifles for the cartridge. The most popular of these are undoubtedly the CZ 550 and Ruger M77 safari model bolt actions. Ruger has also offered their single shot No. 1 Tropical falling block rifle in .458 Lott.
Another cartridge designed for use in bolt action safari rifles is the .450 Rigby, which was introduced in 1995 by the same company that started it all 97 years earlier with the .450 3-1/4" NE. The .450 is based on a necked-up version of the giant .416 Rigby case.
This is a non-belted, rimless, bottleneck case with a small, but very sharp, 45 degree shoulder to maintain proper headspace. The rim and head diameter is .589", the shoulder diameter is .539", maximum case length is 2.90" and the maximum COL is 3.80". The bullet diameter is .458".
This giant cartridge requires an oversize magnum action, the same as the .416 Rigby, which limits its potential popularity due to the limited number of such actions. Rigby offers both bolt action and double rifles for the cartridge.
Rigby/Kynoch factory load ballistics call for a 480 grain Woodleigh SP or solid bullet at 2350 fps MV. As far as I know, the only major US ammunition manufacturer offering .450 Rigby factory loads is Hornady. They load their 480 grain DGS and DGX round nose bullets at 2400 fps MV and 6138 ft. lbs. ME, making the .450 Rigby slightly more powerful than the .458 Lott.
The .460 Weatherby Magnum is a step up from the power of the .458 Lott and .450 Rigby. Billed as the most powerful commercial cartridge in the world when it was introduced in 1958, Weatherby factory loads launch a 500 grain bullet at 2600 fps MV and a thunderous 7504 ft. lbs. ME from a 26" barrel.
This is the most powerful of the standardized .458 African cartridges and likely to remain so, as the .460's recoil is as over the top as its ballistics. Hornady technicians developing reloading data for the .460 Wby. reported badly bruised shoulders. They used a 25 pound bag of shot between the butt of the Mark V test rifle and their shoulders to moderate the outsized kick. This rifle was also equipped with a muzzle brake!
The .460 is based on a necked-up .378 Weatherby Magnum case. The rim diameter is .579", the belt diameter is .603" and the head diameter immediately forward of the belt is .582". The case diameter is .560" right behind the Weatherby double radius shoulder and, despite its nomenclature, the cartridge uses standard .458" diameter bullets. The maximum case length is 2.913" and the maximum COL is 3.75". The MAP is 55,152 CUP.
Weatherby provides factory loaded ammo and Mark V rifles in .460 Mag. As far as I know, the Weatherby Mark V is the only rifle regularly produced in the caliber. Despite its fearsome reputation, the .460 has seen considerable successful use on thick-skinned African dangerous game animals. As always, it is proper bullet placement, rather than raw power, that produces swift and humane kills.
Two commercial American .458's were NOT designed with African hunting in mind. The oldest of these is the .45-70 Government, named for using a .45 caliber bullet in front of 70 grains of black powder.
The .45-70 was adopted by the US Army in 1873 for use in the single shot Springfield Trapdoor rifle. It served the military until it was replaced by the .30-40 Krag smokeless powder cartridge in 1892. By that time, the .45-70 had been extensively employed by civilian market hunters to decimate the great buffalo (American bison) herds on the North American plains.
The .45-70 cartridge is built on a straight walled case with a moderate .0255" of body taper. It has a fairly thick rim .608" in diameter that is typical of black powder cases. The case length is 2.105" and the loaded cartridge must not be more than 2.55" long if it is to be used in repeating rifles.
The SAAMI MAP for the .45-70 is 28,000 CUP. However, most modern factory loads are loaded well under that pressure, about 21,000 CUP according to Speer technicians, in deference to surviving black powder rifles and modern Trapdoor Springfield replicas.
Modern Winchester 1886, Marlin 1895 and Henry lever actions are much stronger than the old guns and can safely take higher pressure loads, while Browning/Winchester Model 1885 and Ruger No. 1/No.3 falling block rifles are stronger yet. For this reason, many reloading manuals have three sections devoted to the .45-70.
Traditional black powder .45-70 infantry musket cartridges were loaded with 500 grain bullets (.45-70-500), while cartridges intended for use in calvary carbines were loaded with 405 grain bullets (.45-70-405) to control the recoil in the lighter carbines. With either bullet weight the MV was around 1330 fps.
Probably the most popular black powder .45-70 rifles with civilians, besides the Trapdoor Springfield, were the Remington Rolling Block and Sharps single shots and Winchester Model 1876 and Model 1886 lever action repeaters. However, many other commercial rifles, including Marlin lever actions, were chambered for the cartridge.
Like other popular black powder cartridges, the .45-70 successfully made the transition to smokeless powder. Today, several single shot and lever action rifles are offered in .45-70.
In addition to a number of single shot Trapdoor, Sharps and Rolling Block single shot replicas, the Browning/Winchester Model 1885 High Wall, Ruger No. 1 and Ruger No. 3 falling block rifles have been offered in .45-70. Modern lever action repeaters include the Browning/Winchester Model 1886, Marlin Model 1895 and Henry .45-70. Marlin and Henry .45-70 carbines with short 18-1/2" barrels have found a niche as "Guide Guns," popular in North America for protection in the field from bears and cantankerous bull moose.
All of the major American ammo manufacturers offer .45-70 factory loads, which are loaded to pressure suitable for Trapdoor Springfields and replicas there-of, usually with 300 grain JHP bullets. For example, Remington offers both a 300 grain JHP at 1810 fps MV and 2182 ft. lbs. ME, as well as a traditional 405 grain Soft point at 1330 fps MV and 1590 ft. lbs. ME.
Specialty ammo maker Buffalo Bore offers full power, standard pressure (28,000 CUP) .45-70 factory loads. These come with a 300 grain JHP bullet at 2000 fps/2684 ft. lbs., a 350 grain JFN at 1800 fps/2518 ft. lbs. and a 405 grain JFN at 1625 fps/2374 ft. lbs. These figures are for 22" barrels.
The 300 grain JHP bullet is basically for Class 2 game (animals up to 300-400 pounds), while the superior SD of the 405 grain JFN makes it suitable for medium size Class 3 animals (up to 800 pounds). The tougher 350 grain JFN bullet can be used on animals weighing up to 1500 pounds, according to Buffalo Bore. Do not use these loads in Trapdoor Springfield rifles or replicas there-of, which should be restricted to 21,000 CUP loads ONLY.
Buffalo Bore also offers what they call ".45-70 Magnum - Lever Gun" loads for modern Marlin Model 1895 lever guns made since 1972, Henry .45-70 lever actions, Browning/Winchester Model 1886 lever actions, T/C Encore and New England Arms Handi-Rifle break-open rifles, Siamese Mauser bolt actions, and all falling block actions made of modern steel (Ruger No. 1, Browning/Winchester 1885 High Wall, etc.). These are high pressure loads loaded way beyond the SAAMI MAP!
Reloaders can also produce high pressure loads, which is why most reloading manuals have separate data sections for modern lever action and modern falling block rifles. Hornady data for modern Marlin Model 1895 lever rifles, for example, shows a MV of 1900 fps with maximum loads behind their 350 grain InterLock bullet (22" barrel). These loads have a MAP of up to 40,000 CUP.
For modern falling block rifles (Browning/Winchester and Ruger) they show a MV of up to 1800 fps with maximum loads for 500 grain bullets (22" barrel). These loads develop up to 50,000 CUP and must not be used in other .45-70 rifles, including modern lever actions (Marlin, Henry, Winchester, etc.).
Buffalo Bore heavy loads and maximum reloads for strong, modern rifles make the .45-70 suitable for hunting the heaviest North American game within the maximum point blank range (MPBR) of the cartridge. This includes bison and the largest bears. Some intrepid individuals have taken their .45-70 rifles to Africa and used them on thick-skinned game there, although there are many better choices.
Unfortunately, not everyone is a reloader and there are always ignorant fools who will try to push the envelope and shoot heavy loads in rifles for which they are not intended, with predictably disastrous results. (These are often the same people who then try to sue the rifle manufacturer for their mistake.) For this reason, in 2000, Marlin and Hornady collaborated to introduce the .450 Marlin, which is essentially a rimless, belted version of the .45-70. The purpose of the belt is simply to prevent chambering a .450 Marlin cartridge in a .45-70 rifle.
The .450 Marlin essentially duplicates heavy .45-70 +P loads and any .450 Marlin rifle is capable of safely handling them, eliminating the possibility of mistakes. Marlin Model 1895 and Browning BLR lever actions have been offered in .450 Marlin.
Current Hornady factory loads use a 325 grain FTX bullet (SD .221) at a MV of 2225 fps and ME of 3572 ft. lbs. (24" barrel). The original .450 Marlin factory load used a 350 grain InterLock bullet (SD .238) at 2100 fps and 3427 ft. lbs., but has been discontinued.
The change to the lighter FTX bullet with its decreased SD would seem to be a step backward where heavy game is concerned, although it provides a flatter trajectory. Regardless, the .450 Marlin is a powerful cartridge and, particularly in short barreled Guide Guns, it is also a powerful kicker that is not for the faint hearted.
Copyright 2016 by Chuck Hawks. All rights reserved.