I almost had one : the barrel on my 6 inch 66-3 cracked not once but twice, so I hesitated to put a 2.5 inch barrel on it and transform it into a snubby. Finally decided to keep it with the second cracked barrel and shoot .38 specials only (and later bought a 586-1M).
http://smith-wessonforum.com/138517693-post13.html