Originally Posted by growr

It known as the tri-action trigger.

1. Single Action-cocked and locked
2. Double action
3. Has a round chambered and the hammer is lowered by pressing forward on the hammer. When the trigger is touched by the trigger finger the hammer travels back to being a single action ...just like being cocked and lock...

Browning and Sig had variants of the same design....never really caught on with the US shooters however.

Randy