I have a 4th edition lyman castboolit manual and was looking for a 405 grain mold and the manual said the lyman 457193 mold was 405 gra in so I found one and started casting and the bullets I was getting were 420 grain! OK fine no big deal I'll use them but my manual doesn't give me load data for a 420 grain in a marlin lever. I downloaded an older lyman manual and it says the 457193 is 420 grain and gives load data for the marlin lever, what gives?