maybe not optimum
I have a pair of 4" GP100s; they wear Pachmayr Decelerator stocks and Millett orange-ramp front sight blades (mostly), and get fed with HKS speedloaders carried in Safariland 333 holders.
The guns get drawn from an Ernie Hill speed holster.
Loads vary from Minor to Major "PF" using 110g/125g/158g/180g JHP to 125g/144g/148g/152g/158g lead bullets to 124g/151g plated bullets intended for the 9mm.
I also use (mostly) a 7.5" Redhawk, but that gun mostly gets a 158g Rainier Major PF load, again fed with HKS, but from the Safariland metal spring-clip holders.
I also use a 5.5" 44 Redhawk, using HKS loaders and 240g LSWC/7.3g Universal (for a 207 PF).
I've also used my (now-gone) 5.5" 41 and 45 Colt Redhawks, fed from HKS loaders. I never competed with my 5.5" 357.
All Redhawks are drawn from my custom-made Milt Sparks HSR. All wear (wore) Pachmayr Decelerator stocks and Millett orange-ramp front sight blades.
(Yes, I tried other stuff, too.)
As soon as I'm fully healed I expect to return to competing with them more often.
E-mail direct for 38/357 load discussion: WESHOOT2@aol.com