Jingles has already said what I was going to suggest. Try either a 148 gr wadcutter or a 158 gr SWC or LRN with something in the area of 3 grs of Bullseye, plus or minus. Just about every fixed sight .38 that is going to shoot to point of aim will do it with that tyoe of load, in my experience, if it is going to do it.

Sometimes small changes can make a difference, but usually not. If this type of ammunition doesn't work, you might have a problem that can't be addressed by load-tinkering, but that doesn't mean you shouldn't try it. Shape and weight of the bullet will probably make the most difference, IMO.