That's a very good question and I have found a couple of older links discussing that subject. Me, I love the 40, titanium cylinder, slab side, and the L frame.

I would buy a 610 N frame, but most likely would still shoot the .40 caliber. I am as fanatical as the .41 mag or 44 special cults!

I love how the 646 was set up by Smith & Wesson, but I also am all for those that want to modify or hop up their Smith's to their liking ala Elmer Keith.

Need info on a Model 646

646 reemed out to 10MM???