On Rugers, I noticed that the SP101 is plagued with under clocked barrels. The GP100's seem to be pretty spot on. With S&Ws, I've seen J-frames and L frames badly canted.

Here's something else to consider: if you look at the opening in the frame where the barrel screws in, sometimes you can see that the opening is slightly off center. Sometimes there is slightly more material on the left or right side of the frame where the barrel screws in. I therefore conclude that a canted front site might not always shoot off, since the front site lean is not the only factor in play here.

Just something to think about.