I don't know of anything identical, no. And as long as you fix that spelling error, I think it's fine. Item powers are more an art than a science, really.
And maybe restrict it to heavy shields only?
Spelling error? Redound is a word that means "reflect."
Redounding is exactly as short as rebounding. Anyway, "redounding" has an archaic feel to it, which I think increases the flavor of a fantasy game like D&D. It's equivalent to calling a shield a crest or an escutcheon.