In a large pot, cook the bacon over medium-high heat until crisp, 5 to 6 minutes. Add the onion, season with salt and pepper and cook, stirring occasionally, until golden, about 3 minutes. Stir in the brown sugar, ketchup, pickle juice and dry mustard and cook, stirring, until thickened, about 2 minutes.
Stir in the pork and beans, pinto beans and burnt ends; cook, stirring occasionally, until heated through, about 10 minutes.
