Ive only gotten 2 45x357s to shoot within my standards and both are light loads.
9mm 147gr XTP BTHP in a MMP blue with 60grs
357 140gr XPB in a PR Orange sabot and a 36cal wad IN the bottom of the sabot also with 60gr or a tad more....not under the sabot. I know it sounds odd but the PR Orange is made for their lead Boattail Dead Centers.
Ive tried 2 200gr bullets. The 200gr FTX and Sierra Pro Hunter. Neither had a bearing surface/ogive length that worked well in a 1-30 or 1-28. I never tried a 180gr but if you can find some cheap there is a slim chance. Wideners still has the 357 180gr Partitions on sale and they would be my choice if i was going to try it again.
You will have to use the PR sabot. The MMP is too short IMO for any long 357. The sabot doesn't fit a flat based bullet well either and the wad seems to help.
Im going to try a few again when my 1-20 arrives but im not getting my hopes up. Sabot failure is likely if they are shot fast enough to make good use of the higher BC. 100grs was pretty much max from the few ive seen that shot well.