In a medium bowl, combine the venison, Worcestershire and vinegar, garlic powder, salt and pepper. Use your hands to mix and evenly distribute the spices. Cover and place in the refrigerator for at least half an hour to help the flavors set in.
Heat a grill (or grill pan) over medium to medium-high heat. Form your meat into 4, ½-inch thick patties and sprinkle with salt and pepper. Cook for 3-4 minutes per side, or until your desired doneness is reached.
Meanwhile, combine the roasted raspberry chipotle sauce and ranch dressing in a small bowl.
To assemble, toast your burger buns, spread a tablespoon or so of the sauce on the bottom buns, top with lettuce, burger patty, cheese, tomato, pickle slices, avocado, more sauce, and the top bun.