My apologies, the wand I was thinking of is "Carbon fiber in epoxy resin, laser drilled, 21.67cm, magically stabilized Bose-Einstein condensate core" from "Better Living Through Chemisty" in the CaerAzkaban Files.
I do agree with your stance about haircuts, at least with what's left of my hair. :D
If he can casually do that number to fix Hermione's hair while his core is almost depleted, it should be "instructive" to see what anger on a full core allows; though I'd not want to be anywhere nearby when he opens that "can of whoop-ass" on someone.