Jumbo Walnut For Sale Diamond nuts jumbo walnuts, in-shell, ranks as one of the most widely consumed nuts in the world. Inside a tough shell, its curly nutmeat halves offer a rich, sweet flavor, and the edible papery skin adds a hint of bitterness. Super Jumbo Walnut has a classic styled thumbhole stock, made from high quality Turkish walnut, featuring a shock-absorbing soft rubber butt pad. The sound of the Super Jumbo Walnut is partly silenced by the full length barrel shroud.