Possible Clues:

• Goes with piece, a revolver?
• What controls access or lets it run wild
• Revolving device for fans?
• Gate by elevated track lets in oddball
• Metro access, and a hint to the circled letters in 17-, 28-, 34- and 43-Across
• Revolver may be used when approaching big game
• Repositions ceramics?
• It results in one admission after another
• Act with elegance, say; it helps to get you in
• It's a revolutionary aid to crowd control, one's admitted