The .458 Lott is a .458 caliber rifle cartridge designed for the purpose of hunting large, thick-skinned dangerous game animals in Africa. It is based on the full length .375 H&H Magnum case blown out and shortened to .
The .458 Lott was designed in response to perceived inadequacies and problems encountered with the .458 Winchester Magnum. The cartridge provides a distinct step up in performance over the .458 Winchester Magnum. A-Square, Česká Zbrojovka/Brno, Hornady, and Ruger have been instrumental in the cartridge's rise in popularity.
Cartridge history The .458 Winchester Magnum was designed in 1956 and was an immediate commercial success. It was a more economical alternative to the English double rifles that were considered the standard rifle type for dangerous game hunting in Africa. The .458 Winchester Magnum was designed to emulate the performance of the .450 Nitro Express in a standard-length bolt-action rifle. However, it soon became apparent that the .458 Winchester Magnum was not performing as anticipated. Several factors contributing to its less than stellar performance in Africa: clumping of its compressed powder charge and use in barrel rifles.
Jack Lott, a big-game hunter and writer from the US, had an adverse encounter with a Cape buffalo in Mozambique in 1959 in which he sustained injuries. He had been hunting with the then new .458 Winchester Magnum. This experience convinced him that a cartridge more powerful than the .458 Winchester Magnum was required when hunting dangerous game in Africa. After the encounter he began a search for a big-bore cartridge which would suit his needs perfectly.
Not finding a cartridge that would fit his needs, he designed a cartridge which he felt would meet his requirements in a dangerous-game cartridge. Jack Lott's original drawings of the cartridge were done on a napkin at a diner. The first cases for the new rifle cartridge were fireformed from .375 H&H Magnum brass into a chamber by using .458 caliber (11.6 mm) bullets which had their bases re-sized so as to fit in the mouth of the .375 H&H Magnum. This method of fireforming left the newly formed cases slightly shorter than the parent cases. The resulting cartridge is named the .458 Lott in his honor. A similar method was used by David Miller and Curt Crum to create cases for their early custom .458 Lott rifles. The creation of the cases began with the casting of a bullet with a shank and which weighed around 260 gr. This bullet was seated on a .375 H&H Magnum case containing of Hercules 2400 powder with some polyester material used as a wadding to hold the powder charge against the primer. This set-up was then fire-formed in rifle with a .458 Lott chamber. The fire-formed cases were then run through a .458 Winchester Magnum full length re-sizing die with a set off of . Once this was accomplished cases were trimmed to tumbled clean. Unfortunately for Miller and Crum, this method of fire-forming of brass led to severe gas cutting into the neck area of the .458 Lott fire-forming rifle after only 200 rounds.
In 1989 A-Square became the first company to offer the .458 Lott as a commercial cartridge. At present, the Triad (Monolithic Solid, Dead Tough and the Lion Load) for the .458 Lott cartridge is available from the company. A-Square also championed the successful SAAMI standardization of the .458 Lott cartridge which took place in 1995. They currently offer the A-Square Hannibal and Caesar rifles chambered for this cartridge.
Design and specifications The objective behind the design of the .458 Lott was to provide a greater case capacity over the .458 Winchester Magnum so as to provide better performance and less compression of the powder charge. The .458 Lott achieved both these objectives by its lengthened cartridge. Furthermore, as the Lott cartridge is in essence a lengthened .458 Winchester Magnum, converting a .458 Winchester Magnum to .458 Lott involves in many cases a simple re-boring of the chamber and if required, a lengthening of the magazine.
The .458 Lott was standardized by SAAMI in 1995 based on specification provided by Arthur Alphin and A-Square LLC. According to Arthur Alphin, the cartridge length was standardized at and the chamber length at because there were many converted rifles in the field that were chambered for the original Jack Lott length. The specifications published by SAAMI reflect this fact.
The specifications for the .458 Lott call for a cartridge which gradually tapers. However, A-Square and few other ammunition manufacturers provide a ghost shoulder for the cartridge which was not included in the specification as standardized by SAAMI. Arthur Alphin chose not to include the ghost shoulder to remain true to Jack Lott's wishes and to honor his memory. The ghost shoulder serves to provide better retention of the bullet in the case under recoil. Like A-Square .458 Lott cartridges, Barnes .458 Lott brass bears a ghost shoulder for this very same reason.
SAAMI compliant .458 Lott cartridge schematic: All dimensions in inches [millimeters].
SAAMI recommends a 6 groove rifling contour with each groove being wide. Distance between lands is and between grooves is . Recommended rifling twist rate for this cartridge is 1-14 in.
Since Lott was an influential big-game hunter and writer, the cartridge gained some attention with professional hunters in Africa. The .458 Lott was soon commercialized by A-Square as a proprietary cartridge. CZ chambered the cartridge in their BRNO ZKK 602 rifles based on the Magnum Mauser action. However, the Lott remained fairly obscure at least in the United States until Ruger offered the cartridge in their Ruger M77RSM Mk II rifles to the American public in 2002. Since then there has been a slow but steady movement away from the .458 Winchester Magnum towards the .458 Lott among professional hunters heading to Africa.
The .458 Winchester Magnum is ubiquitous in Africa. While one might not be able to easily find ammunition for the big Weatherby or the Nitro Express cartridges, due to its popularity one would be able to find .458 Winchester Magnum cartridges. In an emergency, the .458 Winchester Magnum can be fired in the chamber of a .458 Lott.
Performance By 1970 Winchester was forced to deal with the clumping of the compressed powder charge which had been resulting in improper ignition and poor performance. Winchester's remedy was to lessen the compression of the powder column. The result was a .458 Winchester Magnum that was now attaining only about . This was below what Winchester's original design specifications intended. The .458 Winchester Magnum was originally supposed to duplicate the performance of the .450 Nitro Express which could fire a bullet at .
On the other hand, the .458 Lott is designed to provide about more velocity than the .458 Winchester Magnum. The performance goal does not just match but exceeds the original performance specifications of the .458 Winchester Magnum. The cartridge is capable of firing a bullet at from a barrel such as the Ruger M77. This capability easily exceeded the performance that was expected of the .450 Nitro Express and the .458 Winchester Magnum. The Lott cartridge was a distinct step up from the .458 Winchester Magnum and the .450 Nitro Express cartridges. The .458 Lott is also considered a better cartridge for dangerous game hunting than the .470 Nitro Express when judged by its effects on big game.
Due to its development and purpose, the performance of the .458 Lott is often compared with that of the .458 Winchester Magnum. This is inevitable as the latter was the cartridge which the .458 Lott was designed to replace.
Cartridge Criteria Muzzle .458 Winchester Magnum Hornady DGS Velocity Energy .458 Lott Hornady DGS Velocity Energy Values courtesy of the Hornady Ballistic Calculator For the purposes of this comparison barrel a barrel length of is used.
The .458 Lott is able to attain over with a jacketed bullet at safe pressure levels from a barrel. In comparison, many ammunition manufacturers load the .458 Winchester Magnum to velocities between . Hornady's Superformance ammunition being an exception which uses powder blends which at present remain proprietary. The .458 Lott is capable of reaching a velocity of with the bullet which is greater than the velocity reached by Hornady's Superformance .458 Winchester Magnum ammunition. With lighter bullets of , it is able to achieve a velocity of about . These energy and velocity values provide the .458 Lott cartridge a gain of between over the .458 Winchester Magnum in distance. This performance increase provides better penetration and stopping power than the .458 Winchester Magnum against dangerous game.
However, the mono-metal bullets fall short of this velocity threshold due to the need to seat the bullets deeper owing to the length of the bullets and the need to stay within the maximum overall length specification of the cartridge. This is because the lower mono-metal bullets have a higher length to weight ratio than conventional bullets. Manufacturers such as A-Square have chosen to load slightly lighter bullets instead of the bullets.
The straight tapered case of the .458 Lott provides greater flexibility in reloading to lower velocities than bottlenecked cartridges. The ability to reload ammunition to lower velocities with lighter bullets can provide shooters with ammunition with less recoil than the full power .458 Lott ammunition. Nyati Inc., a big bore ammunition manufacturer, has taken advantage of this flexibility and offers ammunition featuring a copper jacket bullet at . They also offer intermediate power ammunition for the .458 Lott as well.
Handloaders can take advantage of the wide range of bullet of useful weights are available in .45 caliber for the .458 Lott cartridge. Bullets ranging from can be loaded for the Lott cartridge. This, together with the ability to load the cartridge to lower power levels, easily adds to the versatility of the .458 Lott. .458 Lott velocities range from with the bullet and with the bullet. Spitzer bullets with better ballistics such as the Barnes X or TSX bullet provides better down range performance over the more conventional .45 caliber (11.6 mm) bullets. The .458 Lott does well with hardcast lead bullets. With these bullets the Lott can be loaded to the power level of the original .45-70 Government cartridge. which was a bullet at .
What the .458 Lott lacks in velocity and energy compared to the .450 Rigby or the .460 Weatherby Magnum, it more than makes up for by virtue of its versatility. Larger volume cases such as the .460 Weatherby Magnum do not do well with powder charges below the recommended minimums. This is due to the erratic ignition and hangfire issues experienced when large capacity cartridges are loaded with small powder charges. The Lott has no such issues and takes well to lower powder charges.
Sporting usage The .458 Lott was designed to be an African dangerous game rifle cartridge particularly for use against heavy, thick-skinned dangerous game such as elephant, Cape buffalo and rhinoceros. It is considered an ideal cartridge for hunting African dangerous game and is capable of taking game from elephant to the duiker. Acceptable bullet weights for the .458 Lott range from . The range of available bullets provides the flexibility to customize loads for specific game species.