I agree and i dont understand the interest for this cartridge that was never suitable for non-professional big game hunters ( and PH!). This cartidge is a symbol of a era and a rifle of this caliber a object of collection. To built a rifle on a shotgun action is, in my opinion, a curious idea. Better you try to built a 450/400NE or, may be, a 470NE? with reserve when you look at a old Rigby or Holland&Holland action. 600NE Doubles are very rare and for this reason very expensive. If i want a Bentley i dont try to built one on a 2 CV Citroen.