Okay, I can into a Spanish made double 12ga that barrels had been collapsed during a hunting trip. The run down of the action.

12 Gauge
Anson & Deeley Action Design
Purdey Double Underbites
Concealed Third Fastener/Secret Bite
Firing Pins are already bushed
Dovetail Lump setup
Double Trigger
Extractors

To my knowledge and from research this should be a good candidate for conversion. Good action design, 3 lockups ext.. But let me know if something bothers anyone. Barrels would be monoblocked in. I will most likely thread and solder.

- I was looking at a few calibers mainly a 470NE, But 450/400, 450 3.25" and 500NE

- Going for a very traditional English look like Westley Richards

- What should my target end weight be for a rifle in these cartridges be around? I know that's subjective but traditionally I was thinking 9.5lbs and up

- What Dia should the firing pins be on Double Rifles. Didn't know if I needed to remake the bushings and firing pins or if the original ones are able to be reused.

- I was looking at 26" barrels, is their a basic contour/profile, or is the profile that of standard sporting rifles(Douglass #4). is their a rule of thumb on bore to wall thickness(.475" + .250" = .725" @ muzzle) type thing

- I see that some are welding in cross bar close to the Hanger for the front iron, its this standard or typical.

This should be a good start of questions I have. I do have "The Book" just need to find it after my move. Will be doing more research and reading existing threads here and elsewhere. thanks for any answers you give