4seventy , we are on the same page, you and I, but one of us is reading it backwards!

I concur the 458 can be made to shoot the way you say TODAY , and all I'm saying is, in the beginning, the cartridge did not live up to Winchester's claims! It is imaterial whether other cartridges did or not, that doesn't change the fact that the 458 WM did not! Addtionally, after the factory ammo was loaded for some months, it produced squib loads, and hang fires because of the factory makeing loads the crushed the powder charges, efectivly turning the powder into a solid block of powder that did not burn properly. My contention is, if there was that much problem with the cartridge when it was first made, why was this not fixed before production? At that time the only way to fix the 458WM, by a handloader, was to reduce the powder load, and reduce the weight of the bullet, because the powders were not available to do otherwise. The other fix, and the simplest one,for the factory, was to increase the powder capacity,of the case,the same way LOTT fixed the 458 with the wildcat 458 LOTT, by useing the full length 375 H&H brass! Necessity is the father of invention!

It is my opinion, regardless, if it takes 50 yrs to get reliable factory ammo, that comes close the factory claims, then, it would seem there was some sereous flaws in the design.

None of this has anything to do with what can be done today, but the cartridge did take some years of fixing,that could have all been avoided by simply makeing the case a little larger in the first place! Wouldn't you agree with that?