So Jim slug your bore and mike the results. Get some fishing sinkers (the soft lead ones with a hole down the center that are just a little to big for your bore).
Oil the bore with a patch, then using a brass rod drive the sinker thru the bore. Use a big hammer and good strokes. You don't want to just tap it thru, but drive it thru.
Mike the slug that results and it'll tell you if you need .319 or .323 bullets.
I'd use the size that most closely fits the bore.
