Prepare a smoker with dampened hickory wood charcoal. The heat inside your grill or smoker should be around 180 to 200 degrees F (80 to 95 degrees C).
Combine the black pepper, oregano, cayenne pepper, chili powder, garlic powder, cumin, salt, and seasoned salt in a small bowl until thoroughly mixed.
Place the chuck roast into a mixing bowl, and rub all over with the spice mixture.
Place the meat into the smoker, and smoke for 1 1/2 hours, turning about every half hour. The meat should be a dark red color, and the edges should be darkened.
Place the meat into a roasting pan, and seal tightly with aluminum foil.
Preheat an oven to 325 degrees F (165 degrees C).
Bake the barbacoa in the preheated oven for 1 1/2 hours until very tender. Uncover the beef, and shred with two forks while still hot.
