I have recently purchased the John Kort designed mould from Accurate Moulds , and aim to produce .429" bullets to use in my 1976 Navy Arms rifle . The rifle slugs out to .430" . I haven't found any Makers marks on the rifle as yet , but believe that it may be a Uberti. I own an old set of Lyman 44-40 dies , but the case neck expander will be too small in dia. for the bullet I want to use . It has been suggested that I use a Lee 44 Special ,or 44 Mag , expander, but I don't know what size these are . All advice in this regard will be appreciated . Thks and regards to all , MZLLDR