Planning to rebore a shot out .30-40 thickwall High Wall to .405 WCF but would like to preserve an option to later chamber it to .450/.400, preferably the 3". Apparently the current .405 rifles are .411 in the grooves tho older Winchesters are found up to .414. The old official twist was 1-10, it is now 1-14. Have not found similar data for the .450/.400 except that bullet diameter is usually .412. I don't see much problem in shooting a .412 bullet through a .411 barrel in a high wall, especially as the .450/.400 pressures are considerably lower than the .405.
However, I don't know what twist would be best wand would appreciate any comments from those forum inhabitants who are knowledgeable about all this.