Wouldn't take much in the way of form dies to make 30-40 from a .405 basic, I've formed a 6mm/30-40 using die bodies you can get from Lee as parts a whole lot cheaper than a form die set.  I think I went down to 35, 8mm, then 30, then 7mm, then 6.5 then 6mm.  From 30 to 6mm it was standard dies, .308, 7-08, 260, then .243, but then we're not talking about making 6mm are we?  From .405 to 35 I think I used a 35 Rem, then a 8mm Lebel, not sure about that, may have been something else, ditto the 35, but I had it figured out at one time without a whole lot of expense.  I'm not the type of fellow keeps my dies organized good enough to go back in the reloading room and figure it out again at the moment, I have a match to shoot tmrw and I'm busy loading.