.45 Colt mostly because it does the same thing as a .44 Magnum at less pressure, about 10kpsi less when both are loaded to the max. I shot .44 Magnums for well over 20 years before it dawned on me that it wasn't the kick that bothered me, it was the concussive muzzle blast. Switched to a .45 Colt and in equal length barrels at equal velocities the difference was notable.
Ruger throats are indeed much closer and more uniform for their .44 revolvers than their .45's, at least in Blackhawks. I've never measured a .45 Colt Redhawk but have measured a few .44 Redhawks and one SRH .44 plus several of each caliber in Blackhawks. If a gun store has a few examples of a particular revolver in either caliber and you want to do a cheap and easy test take a jacketed bullet of known diameter in and measure the throats. It should just slide into the front of each chamber with no wiggle.
If it hangs up or won't go in at all indicating an undersized throat it's really not that hard to open the throats, I've done it on multiple revolvers. Hard core machinists might cringe but I have used Veral Smith's method with complete satisfaction to both open throats and enlarge the "Ruger constriction" where the barrel screws into the frame.
And if you're looking at other than a Ruger, well, never mind...
Gunnery, gunnery, gunnery. Hit the target, all else is twaddle!
