Mickey, The smith I have mentioned has done numerous double rifle conversions including the 45.70. Realizing the .470 Nitro is a cat of another color, he stated that before he would take on the project he wanted to give the shotgun in question a REALLy complete overview. He also mentioned he would be checking the pressures generated by the .470, and mentioned beefing up the bites for a stronger gun. This part I need someone to take the pencil tip and say, "Well, right here we do this and right here we do this, etc." I've read Graeme Wrights Shooting the British Double and have read numerous post here about the complications of getting it done right so am somewhat hesitant to start unless it could be done safely with the outcome, hopefully a good shooter. I'll keep you informed as to what is going on here and will take any and all advice given. Thanks again, Mike