Most commerical loads are in the 50,000psi range. The Freedom Arms can run 65,000psi all day long every day but the Ruger starts seeing sticky extraction at those levels. Remember that Carpenter Custom 465 alloy they chose to build the cylinders with was chosen more for its elasticity than sheer tensile strength. Which is the reason for the sticky extraction. The sixguns really only need that high strength alloy for proofing. If all you ran was factory or handloads in the 50,000psi range, the standard .45Colt Redhawk will do just fine. Ross Seyfried once said that if you have a strong .45Colt, there is no need for the .454 and I would have to agree. With heavyweight cast bullets, added velocity beats you up for no good reason.
Not ragged edge at all. You can't stuff enough slow burning powder in a .44Mag case to hurt a Redhawk or Super Redhawk. Those heavy 340gr loads are suggested for those guns only and are in the neighborhood of 48,000psi. Which is well within the capability of the guns suggested with plenty of safety margin. Remember, there is also .45Colt data for the Redhawk that runs up to and over 50,000psi. So one must ask, what does the handloader really need the .454 for???