Originally Posted by nealtw
It's an extra lock and it should not extend. If you push it in by itself, the main lock part will not go in. In the movies we see people open doors with a credit card, not with that lock!
Yes. . .confirm it for yourself, Prettygoodist. Try to push in the large bolt while the small one is extended, then while the small one is flush with the door edge.
You don't need to touch the knob.
You can't imagine how many of these are improperly installed.