I'm partial to Unique for both regular .38 Special loads as well as +P loads. Unique will clean up once you get to the middle of the charge weights. My M10 likes 4.6gr with a 158gr SWC for a standard pressure load. I've also worked with W231 for little bit as well, 4.5gr with a 158gr SWC shoots really well. I haven't worked up any +P loads with 231 as I think Unique serves that purpose better. That being said I'm certainly aware that W231 is fully capable of +P loads too, I just think that Unique fits that application better.