Hay Sixgun,
Some Darksiders on the Frontier Spot and elsewhere have designed the molds you're looking for. Search for the Snakebite Greasewagon .38's, and the PRS45. They all have HUGE lube grooves. Lee makes them, all in six cavity format, though they aren't listed in the Lee catalog.
Here's a site that shows the casting and pan lubing of the Snakebites:
http://goatlipstips.cas-town.com/casting.html Check the Links section for places to look for the molds. One cowboy that sells 'em is Dick Dastardly. Sorry you had to wait so long for your answer!
Goatlips