Here's a link & a pic. There's some new .410 Ammo out recently which fixes the patterning doughnut you get from rifled barrels. Some people like the way they look, and there are the multi round options. I imagine S&W wants a bit more coin for theirs than the Taurus Judge.
http://www.smith-wesson.com/webapp/...4_750001_750051_768152_-1_757992_757992_image
http://www.smith-wesson.com/webapp/...4_750001_750051_768152_-1_757992_757992_image