I could not chamber .452" long wide flat bullets in 4 of the 6 chambers of my Redhawk.
( number 1,2,4 from the left).
I slugged my chambers and barrel.
The barrel was .4512" with a very slight constriction a the threads.
The throats had various diameters, with the tightest being .4510".
I had 'Cylindersmith' ream the throats to 0.4525". Now, I can chamber and shoot 0.452" Pb bullets with little to no leading.
In my previous post, I forgot to mention. They guy who posted "Ruger has fixed the problem" was somewhat correct.
Apparently, Ruger is attempting to respond to complaints about underdimensioned throats. Now, some throats can be a large as .457".
A huge amount of gas blows by the projectile in the cylinder causing huge loss of velocity and leading problems.