Greyhawk your custom mould makes a good bullet . The larger grease grooves are very good as a BP. bullet. I think the reason I'm getting away with the Lee 340 and its smaller groove's is the fact that I shoot a few rounds and wipe . Being mostly a hunter the first shot from a clean cold barrel is what concerns me most . Just the other day one of the Bp. loads that I was testing would put it's first bullet clean bore on target just right. The next four shots without cleaning went into a small group 2-1/2 " 5 oclock from the first. So I settle for a load that puts all /most bullets into the same spot cold, hot , dirty,or clean. Note my 40/60 wcf and my 45/75 wcf are the most forgiving in this respect .,,,, DT