What is the ruling on killing a rabbit with bullets for training purposes and then burying it, while feeling deep embarrassment about this action?

This act is forbidden in Islamic law because it is a form of animal torture, which the Prophet, peace and blessings be upon him, prohibited. A woman entered Hellfire because of a cat she imprisoned. The Prophet forbade "sabr al-baha'im" (imprisoning animals to be shot at) and cursed the one who did so. He also forbade taking living beings as targets for shooting. Therefore, sincere repentance and increasing good deeds are obligatory.