I've been mulling over RicinYakima's kind offer for same, but I'm not after a vault lock and the other ideas of DeHaas' aren't really what I'm in the mood for. I'm trying to engineer my own thing with a cylindrical bolt, 90 degrees to bore axis instead of skewed, self-cocking, and with minimal drop (like a Farquartzen [sp?] action or Ruger #1 but with slightly exposed hammer). I would prefer a spurless rear hammer that cocks back and downward to be flush with the loading trough, but would have to also engineer a tang safety. Basically I'm looking at the layout of a Falling Block Works Model J, with a lot less drop in the action, in fact level with the barrel on the bottom profile. My biggest challenge so far has been trying to figure out how to attach tangs to the receiver. I'd also really like to use an AR-15 hammer, trigger, and sear but haven't quite sorted out a cocking mechanism or how to extend the hammer face forward about half an inch. Welding on a piece of 1/4x1/2" steel bar and then shaping to make a nose is likely going to be the solution to that problem and a tang safety would be easy to make work with an AR trigger.
I'm currently toying with the possibility of making integral tangs. The challenge is threading a hole in some hard material that sticks out from the faceplate 5". I may be able to make a jig for the faceplate which will brace the receiver billet sufficiently for the boring/threading operation and just mill the tangs out of the billet afterward like real gunsmiths do.