I have been debating for weeks on wich to choose! I have heard that the 250-K is very close to the original Kieth design...but the 429421 was the "original". Has lyman made changes to Kieth's design over the years?? if so, what changes? all I own now is Lee moulds, and in the Midsouth catalog, the Lyman 4 cavity is only slightly more $$ than the RCBS 2 cavity. If you had to pick one, what would it be?