Lyman list a starting load of 18.5gns with 240gn lead bullet for 1574fps out of a 20 inch barrel.
Max is 20.6gns for 1686fps. This is for 44 magnum.
They do list a 44 special pistol load. 10 gns starting and 12,5gn max for a 245gn rn bullets.
Maybe 12gns in a 44 mag case would work?