Thanks, Fiver, I need all the help I can get. I went ahead and done it, bought most of the stuff I think I need and L1A1 convinced me to just make the brass and is helping out with that. I plan on turning the necks to at least knock off the high spots, we'll see how it goes. It is an AR-style rifle (sighhhh....I don't like them much) and the barrel is super-tight, .298x.3075" with a .310" throat entrance, so most of my bore-riders won't chamber. I picked up a new 311299 mould in the hopes that it casts the typical undersized nose and will work. If by some chance it ends up casting the size it's supposed to, I'll use it for my M1A, so win/win.
I remember the 556 stuff you posted, about dealing with big necks and small throat entrances, but unfortunately all that stuff got obliterated in the hissy-fit last January.
Should have all the stuff to finish the rifle next week, will probably put it together at work since my boss has all the necessary tools. If all else fails I'll try the Lee version of Mr. Harris' bullet for now and have Tom cut a heavy mould later. My goal is to mostly do subsonic stuff with heavy bullets.