I have 2 of the 3" GP100s, and I plan on carrying one of them this winter.
Six shots of .357 in a frame that isn't really all that much bigger than a S&W K-Frame.
Other than that, I have a S&W Model 19 that I could give a try at carrying. I have a little OWB holster that fits it. Medium frame, 6-shot revolver with 4" barrel. I think it's do-able with a decent cover garment.
I also have a Charter Arms Mag Pug that is nice and lightweight. It holds 5 rounds of .357 and doesn't break the bank to buy.
Pics of all three: