In the October 2014 issue of HANDLOADER Brian Pearce published data for thermonuclear .45 Colt loads for the Ruger Redhawk. In the article he said that the Redhawk can handle 45k-50k psi loads regularly. I've saved everything he's written about the .45 Colt since probably 2003. In the Bisley Blackhawks he maxes out in the 32K psi range.
I personally have no interest in lighting off and trying to hang onto that much horsepower, but it's nice to know that I can go up a ways past Hodgdon's published 30K psi loads with no real concerns especially with heavier bullets.
Problems arise if you have more than one revolver in .45Colt. Loads that are safe for a Redhawk would likely destroy a SAA, or even a Model 25 Smith. I don't want to worry about keeping the hot stuff out of my 25, so I don't load any thing that it can't handle safely.
