Shape into 12 patties for smaller, quarter-pound burgers.
Microwave vegetable juice in glass bowl at HIGH 1 minute. Add bread pieces; let cool. Combine, using hands.
Combine vegetable juice mixture, ground chuck, and next 3 ingredients. Shape into 10 patties.
Grill patties, covered with grill lid, over medium-high heat (350° to 400°) 6 to 8 minutes on each side or until beef is no longer pink.
Spray cut sides of buns with cooking spray; place buns, cut sides down, on grill rack; grill 2 minutes or until lightly browned. Serve hamburgers on buns.
Note: For testing purposes only, we used V-8 for vegetable juice.