In the idea of a Taurus Judge and the new S&W Governor, I've been pondering the idea of a multi-buckshot cartridge for the 357 Magnum. Perhaps either a 357 Magnum case (or a 357 Maximum case) with #000 or #00 buckshot. Unfortunately my 357 Mag revolver doesn't allow for the 357 Max case to slide all the way into the cylinder, otherwise the 357 Max case would be ideal for a shot shell case.
Some searching, came across these products...
REMINGTON’S MULTI-BALL AMMUNITION http://www.americanrifleman.org/BlogEntry.aspx?id=1790&cid=25
Strike Three Self Defense .357 Magnum Pistol Ammohttp://www.centerfiresystems.com/am357-s3.aspx
#00 buckshot would measure smaller than the .357 and would probably pick up less rifle spin than a tight fitting #000 lead shot.
#000 buckshot .360" 70 gr.
#00 buckshot .330" 53.8 gr.
I am not going to attempt hand loading the idea any time soon, but am interested on investigating where one would start with a powder charge and type of powder (fast or slow?). Three #00 buckshot would weigh in at about 160 gr. Would using other .357 recipes for a 160 gr lead bullet be a reasonable place to start?