Anyone have a preferred load recipe using Unique and 158-grain cast SWCs for .38 Special?

I'm loading up some rounds for my S&W Model 15. Bullets are 158-grain SWCs at ~17 BHN. Planning on 4.5 grains Unique, but I'd like to hear your thoughts on this load. I definitely want to stick with Unique.

Loads will be used for killing rocks, paper and rabbits.

Thanks much!!