Truthfully, I've never measured either the barrel or cylinder throat diameters of my two .41 Magnums, a Taurus and a Freedom Arms. But .410" diameter bullets, both jacketed and cast, work great for me in either gun.
I guess it depends on the bore diameters, as well as the cylinder throat diameters, of your two Rugers, what diameter bullets will work for you. Concidering the fact your cylinder throat diameters are only .411, it sure doesn't sound like .412" diameter bullets are going to be all that easy to chamber.
How do they shoot though? Accurate? Leading? I ask because if they're accurate and you're not having leading issues, you COULD have your cylinder throats reamed a little. Or, who knows - maybe reaming the cylinder throats would solve the accuracy and/or leading issues if you're having any. I myself wouldn't have them reamed. I'd try some .410" or .411" diameter bullets first. But they're not my guns.