I too carry the SP101 3 inch. I have a pair of Tactical Tailor first aid pouches, one on each side of my pack belt. The left one carries first aid gear, the right one the 357mag. The pouches have a dual zipper that meets at the top, inside is a elastic band against the back of the pouch that holds the 3 inch revolver quite well. Leaving the zippers apart an inch or so allows me to plunge my hand into the pouch for rapid access. Once the pack comes off, the gun goes into the front pocket of my hiking shorts/pants.
Allan
Allan