In a large bowl, mix together beef, pork, bacon, onion, mushroom soup, panko bread crumbs, egg and BBQ sauce.
Cover bowl with plastic wrap and place into refrigerator for 2-4 hours.
Preheat grill to medium-high heat.
Form meat mixture into 6 equal sized patties.
Place patties onto preheated grill and cook for 6-8 minutes per side, or until internal temperature of each patty reaches a safe temperature of 165 degrees.
During last few minutes of cooking, add cheese slices to tops of patties and cook until melted through.
Remove from heat and serve on toasted hamburger buns with lettuce, tomato, and red onion slices.