No, I wasn't worried about it and it doesn't make any difference whether the rifling has a left hand or right hand twist, simply thought it was interesting that all the S&W pistols (5 different models, 2 different calibers) on my bench at the time with the exception of the 745 were left hand twist.

I thought maybe it was something along the lines of S&W revolver cylinders turning counter-clockwise (viewed from the rear of the revolver) and Colt revolvers turning clockwise which is due to the different designs of the revolvers.

I don't know how S&W rifles their barrels but, for production purposes, one was think the machinery would be consistent (think ISO-9001 and Six Sigma). Then again, maybe not...

bls