I will offer up a suggestion , what I found has helped me . I found a case gauge very helpful . Occasionally I had a case that the sizing die couldn't totally resize . A slight bulge was still there near the base . The last time I resized / deprimed 50 cases I had 5 that would not fit into the case gauge . I bought the LEE push through sizer . It fixed my problem . I also found that Berry's Bullets sized .356 , heavy plated , for 357 sig the most accurate vs .355 . For powders I liked Accurate #9 and Alliant Blue Dot . That has been my experience in my Sig P320 converted to 357 sig . Regards Paul