Hey I'LL MAKE MINE
That Lee bullet is used by several Lawnsteel players. One person opted for the higher BC of the round nose and as you suggested, it does come up short on knocking down steel. Lyman and Saeco make a "cowboy" bullet design which are the most popular. The Saeco looks just like the ones shown on "Cast Boolits" logo. The Lyman bullet has an ogive of 2 on the nose and a bevel base. Depending on the age of the Lyman mould, the lube groove may be flat or curved. Again, you are correct about bullet fit and with these lower operating pressures it becomes critical. The few who use commercial and jacketed stuff struggle with loading for accuracy. With the low velocity a soft alloy is actually much more effective. Softer alloy will yield a heavier slug and the predicted weights from given moulds are based upon Lyman #2 alloy being used. Also the casting temp can be reduced when alloy approaches higher lead percentage. Typically tin is added to reduce weight without making a significant rise in hardness along with reducing the casting tempature. Gosh, it sure does make a nice shiny bullet. The Lee mould does a fine job and those who use them swear by them. It is not difficult to make Lawnsteel ammunition, but it is different. You may find your wesson oil to be far more accurate than imagined. Soon as you get a chance, shoot some Lawnsteel ammo and tell us all about it.
Roy