What do you mean by "correct"?
If you're only wanting to know the twist of your rifle, do the old cleaning-rod trick. Use a fairly tight patch. Make a longways mark on the side of the rod (Pentel, for instance) a bit over a foot from the patch. Push the rod down the barrel and stop when there has been one full revolution. Mark a spot on the rod, at the muzzle. Remove the rod and measure the length of travel. That tells you "One turn in xxx inches."