I've posted this question on Accurate Reloading and thought it best to also querry here. I have a Model 24 Winchester 12 guage that I would like to convert to a double .470 Nitro. Will it withstand the pressure of the .470 Nitro or is it going to shoot off the face with standard loads? The shotgun is very sound. The smith I've talked to about the project said he normally does them in 20 inch barrels. I would prefer 22 or 24 inch. Any recommendations on the 20 versus the 22/24 inch? I've also heard the Model 24 has the round extractor that had a tendency to slip over the rim of the shell and this problem would need to be addressed. There was also a problem with something else I can't at this time remember but as I recall it was nothing major and could also be handled by a competant smith. If not the .470 Nitro, what is the largest caliber one would recommend on the conversion? Thanks and all advice/help will be greatly appreciated. Mike