I can agree using a action that was in the start a shotgun action may not be its intended use, but since even the early makers used primarily the same as their shotguns with some additions I see the reason that it is a viable solution vs making a new action from scratch. I only consider this action that I have a candidate as it has a 3rd lockup/bite, I would not consider a double underbite only IMO for a Nitro Express cartridge. I wish this one was bolstered for reinforcement but its a pretty beefy action considering.

As for weight, the 9.5lbs came from some of the published info I have found by searching other English made doubles in 470NE and like cartridges. I know that the English makers of the day did run a bit light, but that's pretty much a English tradition, as even their shotguns are light dainty things. I don't mind recoil, especially if it is a low pressure cartridge. I shot a custom Ruger 416 Rigby N01 and I think its 8.5lbs, and is not a problem at all. Im not one for the high pressure snappy recoil like that of 7mm mag 460wby ext... that's just a violent recoil vs the big push.

- What diameter do I need to make the new firing pins and bushings to as well as firing pin protrusion. Right now I would just go by the standard of most bolt guns an like.

- Also what is a good muzzle diameter on a Double in 470NE? I know I gave a example of .725" But didn't know what actual builds are running and the weight of those rifles?