Light a grill or preheat a grill pan. In a bowl, season the turkey with salt and pepper and gently knead in 1/4 cup of the barbecue sauce. Shape the meat into four 4-inch patties, about 3/4 inch thick. Brush with oil and grill over moderate heat, turning once, until nearly cooked through, 7 minutes. Brush with the remaining 2 tablespoons of barbecue sauce and cook for 1 minute longer, until cooked through and lightly glazed. Transfer the burgers to the buns and top with pickled jalapeños, Swiss cheese and pickle chips and serve.