There is no denying the fact that some of the older 458 Win ammo gave erratic performances due to a combination of age, compression and heat. But to be fair one must also realize that original Kynoch loads also fail to reach anywhere near their advertised velocities. Ross Seyfried tested original Kynoch 450/400 loads and was suprised when they barely reached 1900fps - but it still has a good reputation. Every original Kynoch load that I have ever tested, as well as those results published by a few astute Aftican gun loonies, give real world ballistics between 2000 to 2100fps (rather than the advertised 2300-2400fps) and this has been proven over and over to be all that is needed. Even Jack Lott was only looking to acheive these velocities.
With modern powders it is easy to duplicate - and surpass- these ballistics with the 458, with no compression or pressure problems.
If you want more velocity - for whatever reason - and can afford the price - then go ahead and buy a bigger round. But don't discout the experiences of Harry Selby ( when he traded in his 416 Rigby he bought a 458 Win ) , Don Heath, Charlie Haley, Richard Harlan or Finn Aagaard and expect me to believe the round is ineffective and can't safely reach 2100fps with 500 grain bullets.
Phil,
This is all very true. Geoff McDonald from Woodleigh told me that he had over the years, chronographed most of the original British Nitro rounds and at that time, had never seen a single one live up to factory velocity claims.
Most negative comments about cartridges, any of them, but the .458 in this case, usually come from people with little first hand experience.
I have owned several and tested several more, in climate equally as hot as anything Africa has to offer and never had a failure, but, I am not using decades old factory ammunition either.
John
