I have a 6" 686-4 and a 6" Ruger GP100. When it came time to mount a scope on one of them for silhouette competition, I chose the GP100. The GP is more accurate than the 686 with every load iI have tried. Only high velocity loads with heavy bullets brings the 686 close to the GP. As far as I know, the GP has a higher rate of twist than the 686. That would account for the accuracy difference. The original Python also has a higher rate of twist than the M28 and was more accurate, according to Jerry Miculek; although he chose the M28 because of the better DA trigger action. If this pattern is true, and the new Python has a good DA action, I predict huge sales for it.