Maybe Ruger is referring to the commercially loaded, cast 9mm loads with the bullet being seated out too far and preventing the cylinder from turning. With a few chambers loaded with something of this nature, the gun would be unusable until you shaved off the tops of the bullets. I have a SP-101 in 32 Magnum and that's all I shoot is cast loads. It saves so much wear and tear on the gun by using them too. Unless I had a chambering issue or some serious leading, I would shoot cast loads in everything I owned. A truncated cone is more user friendly than a round nose for a revolver so my vote says yes, if it works, why not use it.
