1. A rail interface system for connecting an accessory component to a weapon component, the interface system comprising:the weapon component having a first rail surface, a second rail surface, and at least one through rail opening extending between the first surface and the second surface, the rail opening defined by a peripheral edge formed between the first surface and the second surface, the peripheral edge having opposed end edges; and
the accessory component including an accessory body having a contact surface and a shoe connected to the accessory body for sliding movement along the contact surface between a locked position and an unlocked position to secure the accessory component to the weapon component with the contact surface abutting the first rail surface,
the accessory body also includes a body protrusion extending from the contact surface, and a spring operatively engaged between the protrusion and the shoe to urge the shoe toward the locked position,
the body protrusion and shoe extend through the rail opening and restrictively engage against the opposed end edges when the shoe is in the locked position and are spaced from the opposed end edges when the shoe is in the unlocked position.