The safety works by locking onto the firing, holding it back. When the safety is off, the trigger sear is holding it back.
This CAD video will give you a good idea.
To see how the safety locks on, pull both from the bolt, remove the spring and you can slide it off/on/rotate and you’ll see how the firing pin mates with the safety stem.
Be careful not to pull the trigger while locking the bolt. There is a small window where the safety and firing pin will lock with the receiver and you’ll have to remove the action/bolt release in order to manually cock the firing pin with a screwdriver or similar tool to release the bolt.
I'm still not seeing anything out of the ordinary when I pulled the bolt out and rotated the end cap off -- maybe I am just not seeing what parts should be locking up when the safety cap is rotated.
My safety is still functioning when the rifle is cocked, but no longer locks when it is un-cocked. Strange thing now is that the safety cap will not rotate to the locked position when I have snap caps (dummy shells) loaded up -- is the safety feature supposed to function with the rifle cocked and loaded? I should think this would be a key use of the safety.
I really prefer to keep a snap cap loaded up so the firing pin can have something soft to strike (hard rubber 'primer') if the trigger is pulled.