Has anyone tried Winchester's Supreme 500gr.Nosler partition at a claimed 2240ft/s. Velocity if true would be almost 100ft/s faster than Hornady's Superformance loading and only 60Ft/s less than that company's Lott load.

If Winchester's claim is legit it would certainly help to rehab the .458's reputation.

I own a Browning High Power Belgian Safari grade in that caliber and it is a beautifully made rifle if slightly on the light side.

I would love to try that load on Buffalo this summer.

The 458 Win is a great and now classic DG cartridge, despite all the controversy. Let us know how this load works out. Should prove definitive on buff.

Check the barrel length they used. It's common to list the high velocity with an abnormal long barrel.

Back in the late 70's Weatherby ammo was shot from 28" and 30" barrels for "velocity" but most were 24-26" long.

That was a real load of crap, but the consumer has become much more aware of this and I think it may be more closely watched not?

Good point. No information on test bbl length used by Winchester. However, the Barnes load data with a 500 gr. banded solid bullet in a 24" barrel shows an MV = 2194 fps. With some of the new blended non-canister powders the manufacturers are using MVs like Win lists may be achieved.

WanabeBwana, Good way to resolve it is to chrono the load from your rifle or one with bbl length you plan to use - then we'll all know.

I have chronoed 500 grain bullets (though not Noslers) at 2200 fps with a .458 Model 70 and a 22" barrel using AA2230. No apparent pressure signs. I don't see why it would be difficult for these new loads to meet their claimed velocities in a 24" barrel.

I never saw an experienced .458 owner "tip the bucket" on it. I have however, seen a great many .416 owners who do not have that experience comment unfavorably.

It also appears that equal experience with the two calibers is somewhat limited. That's ok, "mine's better than yours" is the traditional resolution.

I wont be able to answer your question, but I will make an observation that may be of interest or not.

After 20 years of shooting various 458's, a slower muzzle vel. of 2100 fps or even 2000 fps will kill buff just as well as 2200 fps and your felt recoil will be about 40% less. A lot of folks have found fault with the 458 Win. mag. because of low speeds, but when I load my own ammo, I load 500gr. bullets at just around 2100 fps because they work just as well as 2200 fps. I can produce handloads that will achieve 2200 fps out of 22 inch barrels and even had one rifle custom built for working in Alaska, that would achieve 2200 fps with its short 18.5 inch barrel and 500gr. bullets--that rifle utilized an Obermeyer barrel.

And this is an entierly different subject, but honestly, you're better served with 450gr. bullets (both softs and solids) for any African game, as the 450gr. bullets will stabilize better terminally and will normally out penetrate the 500 gr. bullets if all else is equal, as those lighter bullets stay "nose forward" better than the somewhat wobbly 500gr. bullets. Sometimes 500gr. bullets work very well and sometimes they dont, but the 450gr. bullets always do, assuming proper construction.

And speaking of recoil, I have found that 450 grain bullets at 2250 seem to kick a lot less than 500 grain bullets at 2200.