No! If you intend to use a .429 diameter bullet then slug the bore before you do so to determine if you can safely use a .429 diameter bullet or if you must use one of .427 diameter or even smaller.
My old Lyman manual lists the range of diameters from .425 - .429. The groove diameter on the rifle used in the testing was .432 but only .426 on the revolver, so for safety sake, slug the bore and then use bullets of proper diameter. jmtcw.