A mounting bracket for attachment to a firearm's tactical rail, the mounting bracket including a “C” member having a web and lateral and oppositely lateral hooks, the web further having a seam dividing the “C” member into lateral and oppositely lateral halves; extending and retracting slide bars and slide channel combinations connected to the “C” member's halves for movements of the halves between first and second positions, the halves in their first positions displacing from each other for rail receipts and releases, and the halves, upon opposite movements, capturing the rail between the “C” member's lateral and oppositely lateral hooks; and latching pawls connected to the “C” member's lateral and oppositely lateral halves for, upon movements of the halves to the second positions, alternatively resisting and permitting movements of the halves to their first positions.