Barbecue Sandwiches

Ingredients (11)

• 4-1/2 pounds ground beef
• 1-1/2 cups chopped onions
• 2-1/4 cups ketchup
• 3 tablespoons prepared mustard
• 3 tablespoons Worcestershire sauce
• 2 tablespoons vinegar
• 2 tablespoons sugar
• 1 tablespoon salt
• 1 tablespoon pepper
• 18 hamburger buns, split
• Sliced pickles, optional