What must you never do with a loaded rifle?

The correct practice involves never setting down a loaded rifle unattended. This action poses a significant safety risk, as it might lead to accidental discharges or unauthorized access by individuals who may not be trained in firearm safety. Proper handling requires keeping a loaded rifle under constant supervision, ensuring that it's pointed in a safe direction and that only individuals trained in its use are present to manage it. Safe handling practices dictate that a loaded rifle should always be under control and accounted for; setting it down could inadvertently place others in danger.

The other options, while also important safety considerations, do not capture the immediate hazard posed by leaving a loaded rifle unattended. For example, passing a loaded rifle to another person does entail safety risks, but as per standard protocols, certain procedures can make this safe, such as ensuring the recipient is ready to accept it. Pointing a rifle away from the target is fundamental safety practice, aimed at ensuring that the firearm is not directed towards people or unintended targets. Unloading the rifle is a necessary action when transitioning between uses, but it doesn't pertain to improper handling in the context of setting the rifle down.