Yeah, that or just buy a lead hardness tester. They aren't expensive and if you're that serious about the hobby it's nice to be able to correlate new alloys with previously favored alloys via tangible numbers, ie: the Brinnel Hardness System. Pencil leads must be sharpened exactly identically and applied with the exact same force or the results are merely "wide ballpark" in nature.
"You can lead a man to logic, but you cannot make him think." Joe Harz "Always certain, often right." Keith McCafferty