1. Prepare grill to medium-high heat.
2. Combine 1/2 teaspoon salt, pepper, and sirloin. Divide meat mixture into 8 equal portions, shaping each into a 1/4-inch-thick patty. Lightly coat both sides of patties with cooking spray. Place patties on grill rack; grill for 3 minutes on each side or until done.
3. Combine shallots, Worcestershire sauce, mustard, and butter in a small bowl, stirring well. Cut rolls in half horizontally. Spread shallot mixture evenly over cut sides of rolls. Layer 1 patty and 2 pickle chips on bottom half of each roll; top with top halves of rolls.