What is well closed has no bolt locking it, but cannot be opened.

Then the bolt locked back: he was out of ammunition.

There was no move to draw any bolt or bar locking that cage.

He fired some shots but then the bolt locked back on an empty mag.

A bolt locked the door, but I was able to bang it off with a couple of blows from a sledgehammer.

If an M16 series magazine is used, the bolt will not lock back after the final round is expended.

The gun stopped firing, and the bolt locked.

Like a well-crafted mechanical bolt smoothly locking into place, the vessel became battle ready.

Vernet pulled again, but the bolt wouldn't lock.

The Zastava M21 is gas operated with a rotating bolt locking system.