Grease the grill grate by brushing it with oil. Preheat the grill to medium.
Mix together the beef, salt, black pepper and butter in a large bowl. Form the beef into 5 patties about 1-inch thick. Place on a baking sheet.
Place the burgers on the grill, cover and cook, turning once, until the burgers reach the doneness you like, 7 to 9 minutes for medium-rare. Just before the burgers are done, put the buns on toward the back of the grill to toast.
Sandwich the burgers in the buns and top with the bacon, some lettuce, onion, tomato, ketchup and mayonnaise.