For the best accuracy, all the throats in a cylinder should be the same.
Strangely, in the 7 Ruger 45 colts that I have; (9 cylinders, two 45 acp)
this was not the case. I found several different sizes in each cylinder.
So...
I reamed the throats of all my Ruger 45s to 0.4525" including the acp...