I don't believe that these guns had any "special" tuning, etc. However Ruger is developing new manufacturing techniques that tend to hold the quality of individual parts to tighter tolerances. For example, the old way of machining cylinders was to drill three chambers at a time using multi spindle drill heads, and indexing fixtures on very heavy drill presses. That's why many old single six's especially ( small holes are harder to drill that way) shot groups that resembled a flying bird. Three this way, and three that. Starting about three years ago, Ruger started processing the chamber machining in cylinders on CNC machines that are capable of controlling size, and location of chambers, and throats much more closely. When you add enough of this kind of thing up, it makes a real difference in how a gun feels, and shoots. Like all gun companies, they have a ways to go, but they sure are headed in a good direction.