Preheat grill to 350° to 400° (medium-high) heat. Whisk together mayonnaise, sour cream, apple cider vinegar, 1/2 tsp. salt, and 1/4 tsp. pepper in a large bowl. Add coleslaw mix; toss to coat. Cover and chill until ready to serve.
Combine ground sirloin, steak sauce, and remaining 1 tsp. salt and 1/2 tsp. pepper. Gently shape mixture into 4 (4-inch) patties.
Grill patties, covered with grill lid, 4 to 5 minutes on each side or until beef is no longer pink in center. Serve on hamburger buns, and top burgers with chili and coleslaw mixture.
Note: We tested with Fresh Express 3-Color Deli Cole Slaw.