458x2" (458x2" American)

Historical Notes:

This belted cartridge was designed by Frank C. Barnes in mid 1962. It is the 458 Winchester Magnum shortened from a case length of 2.5 inches back to an even 2 inches. It is designed as a medium power, big bore cartridge for North American hunting conditions and game. It is short enough to work through either standard or medium length rifle actions. The original rifle was made up on the short Remington Model 722 action as a lightweight carbine with a 21 inch barrel. This provides an extremely powerful rifle for its size and weight of 7.25 pounds. The cartridge also works very well in the rebarreled Winchester Model 94 Big Bore rifles.

General Comments:

The standard 458 Winchester Magnum and the 460 Weatherby Magnum are overpowered for North American big game. Both have very heavy recoil and require heavy, expensive rifles. Efforts have been made by various designers to provide a medium power big bore cartridge more suited to American needs. The 450-348 and 450 Alaskan are examples of this, but they are rimmed cases suitable only for lever action or single shot rifles. The 458x2" American is intended for 300 grain to 405 grain bullets. It gives good performance with these and is adequate for the heaviest North American game at a short to medium range. It would also be quite handy for any but the more dangerous varieties of African game in close cover. Case dimensions and capacity are similar to the 45-70, but modern actions permit heavier loads. This cartridge is, in effect, a belted 45-70 rather than just a shortened 458 Winchester Magnum. Ammunition can be made from 458 Winchester Magnum brass. Dies are available from RCBS and chambering reamers from H&M Tool Co.

Source: Cartridges of the World

458x2" (458x2" American) Reloading Data
Bullet (grs.)	Powder / (grs.)	MV	ME	Source
Cast Bullet Load Data
210	IMR 4198 / 23.0	1285	778	Lyman #457127
250	IMR 4198 / 28.0	1828	1860	Lyman #454485GC
300	IMR 4198 / 25.0	1370	1257	Lyman #454485GC
405	IMR 3031 / 45.0	1535	2120	Lyman #457491
Above cast loads are all economical, accurate and pleasant to shoot. All but the 210 grain bullet are adequate for deer out to 150 yards.
Jacketed Bullet Load Data
300	IMR 4198 / 36.0	1650	1820	Hornady SJ rifle bullet
300	IMR 4198 / 40.0	1825	2223	N/A
300	IMR 4198 / 55.0	2412	3900	Fred Barnes SP
300	Hi Vel / 58.0	1984	2635	N/A
350	IMR 4198 / 51.0	2209	3810	Hornady SP
350	Hi Vel / 56.0	2034	3240	N/A
405	IMR 4198 / 51.0	2110	4005	Winchester SP
405	Hi Vel / 56.0	1949	3422	N/A
Jacketed bullet loads are intended for big game. All loads tested from a 24 inch barrel, average temperature 78° F, 458 Winchester Magnum cases and Federal #215 primers.

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