Simple answer, your rifle does not have a safety.

You have what is commonly called a 'Lee Metford bolt'.

There is a half cock, but that was never prescribed to be used other than as the built in feature that if the sear were to slip off the bent at full cock, it will automatically fall into half cock and not fire.

The military version of the early Lee Metford did not have a safety either. But it had a magazine cut off plate which when closed, stopped the supply of cartridges from the magazine. The plate had to be opened in order to load from the mag. Fire orders were given by an officer when to load, fire , etc. In the combat of those days, the only time that there would be a chambered round in the rifle was when the muzzle was pointed at the enemy ready to fire. A rifle would never be carried 'locked and loaded'.

How does one use such a design for sport and hunting?... Answer = very carefully!