While there is truth to this but, I, the OP was never talking about "Colts." I was always talking about Ubertis 1873 reproductions, which are stronger and more rugged than Colts: modern metallurgy and machining and don't have the weak hand spring which is a source of much trouble with "Colts." I have a Cattleman II which has a retractable firing pin eliminating the need for what I consider a very silly practice of walking around with five rounds in a six-chambered revolver (I've always wondered why Colt never incorporated the feature of allowing one to lower the hammer between chambers on the 1873...this feature exists on my 1860 Army, and I suspect on earlier designes so I'm sure they were aware). Ubertis have forged frames unlike cast Rugers (which is why Rugers are always overbuilt and chunky looking). Cylinders are always machined out of a bar, and are the weakest link in a revolver according to Keith, Linebaugh, Elgin Gates and everybody that I know of who has experimented to the point of destruction. I believe them.You can always over pay to have the finish look real cool, like with Turnbull, but you can't make a Colt that is as strong and rugged as a Ruger.
I have a Flattop new model Blackhawk in 44 special that has digested plenty of Keith loads without issue whatsoever. It's cylinder measures 1.673". My Uberti Cattleman II (357 mag) measures 1.671". Flatops are available with 45 ACP cylinders. According to some so are Ubertis which makes sense which makes me think Ubertis are plenty capable of a 45 Colt + P load. I doubt they are capable of "RUGER/TC" loads you find in load manuals that are intended for the much larger SuperBlackhawk cylinders for the 44 magnum. This would be hazadous I think. But again I'm not talking about 45 Colt loads that match 44 Magnum energy. I'm talking about 45 Colt loads that send the standard weight bullet (~250) grains along at 1000 FPS or so.