The .458 Winchester is already too short to optimize the velocity of the bullet weights it was designed to shoot. Reinventing the .45/70 is not a step in the right direct, and with cartridges of this power level a short action is of no advantage as the additional few ounces of weight from a magnum length action is your friend not your enemy. IMHO, too often the solution to the shortcomings of the .458 Winchester, albeit an affordable solution, is to rechamber to the .458 Lott; but this retains the disadvantages of a straight wall cartridge. A better approach would be to build a .458-.375 Ultra Wildcat, similar to the .460 G&A which meets or slightly exceeds the Lott's ballistics without the disadvantages of the straight wall case, which includes feeding issues due to nose heaviness, cycling issues if the belt of the ejected case catches on the mouth of the cartridge in the magazine, and a limited powder capacity which does not exceed the bore diameter.
