Let us know what the cast boolit diameter is after you begin casting.
I will. Unfortunately, casting wont happen soon, a friend, who is well equipped, is over 200 miles away. The problem is that we are still under some sort of lockdown. Not official, but everybody minimizes contacts and travel because of corona.
Regarding bullet dia, nominal size as cast should be .359". However, I discovered that bullet is designed to fit into cylinder chamber even if its dia is larger than chamber one. Since chambers on my S&W 686-3 are .358" dia, I decided to ask MP-Molds to make me tad larger nests (see NOTE). Hoping to get as cast .360", and lube-size on .359".
I had chosen this mold after consulted other folks who used it considerably. All of them mentioned that this is one of consistently the most accurate bullets they tried, in almost all revolvers. As soon as I have first batch cast, will try and let you know results. Unfortunately, Bullseye powder is very difficult to find in my area. Will have to go with Lovex or VVO powders. Apparently, one of better powders for mid velocities is AA No. 5. From what I found, AA was purchasing and selling No. 5, that is actually Lovex D 036-03
https://www.ar15.com/forums/Armory/Shooter-s-World-Lovex-powders-opinions-on-performance/42-485088/ . So, if you have a proven load for 357-155/158 bullet, at 1000-1100 fps, using AA No. 5 or one of VVO powders, I would appreciate your help.
NOTE: If you go on their website with bullet selection
https://www.mp-molds.com/product-category/molds/ (left side), you will see diameters listed, and all molds made to that particular diameter. However, if you want specific bullet, but (for example) there is .358" only, and you want .360", you can contact them and the could make different dia at no additional cost. The only problem is that particular mold cannot be made right away, because they make them in batches. However, if you let them know enough in advance, when they have next run, they could make mold you want, with different dia you specify. They could do that because cavities are made by peripheral milling using CNC mill. Another advantage of such process is that cavities are consistent. And very round, as if they are done on a lathe.