What is the best way to stop a runaway gun on the Mk-19 if it must stop firing?

The best way to stop a runaway gun on the Mk-19 is to lower one charger handle. When the gun is firing uncontrollably, the first step to mitigate the situation and regain control is to manipulate the charging handles. Lowering one charger handle will stop the chain reaction that keeps the machine gun firing by interrupting the belt feed system. This action effectively halts ammunition from being fed into the chamber, allowing the operator to bring the weapon under control.

While releasing the trigger might seem intuitive, it will not be effective if the gun has gone into a runaway condition, as it may still fire as long as it has ammunition feeding into the chamber. Engaging the safety is another important safety measure, but it does not address the immediate problem of a runaway gun actively firing. Pulling the charging handle back could be beneficial for immediate control, but without lowering one of the charger handles, ammunition will continue to feed into the weapon. Thus, lowering one charger handle is the most decisive and effective action to safely stop the gun from firing.