The first dead bolt snapped shut, followed a moment later by the second.
The dead bolt snapped and the door swung open slowly.
The bolt snapped like a twig and the door crashed open.
As Rick followed him, he heard the bolts in the door automatically snap shut.
The break away bolt then snaps, allowing the projectile to move forward.
As soon as he stepped through the door, bolts snapped.
Then several bolts snapped aside and the door opened.
He worked the bolt on his Weatherby and the first bullet snapped into place.
A few seconds later, a bolt snapped back and the great door slowly fell open.
There was a single shot, and then the bolt snapped shut on an empty chamber.