I think you would do better with 38 brass. I have shot hundreds of Berry's 148 Gr HBWC in my 686 with 3.2 Grs of Unique in 38 cases with a COL of 1.180
Wife shoots same load in her 637 with great accuracy. IMO the case volume of the 357 is detrimental to good accuracy with such light loads.
Also I do not recommend the lower end of the loading charts with these bullets, you will stick one in the barrel, been there!