What must be secured into the magazine well during double feed remedial action?

The correct choice, securing a new loaded magazine into the magazine well, is essential during the double feed remedial action in firearms handling and emergency procedures. When encountering a double feed, the goal is to resolve the malfunction quickly and effectively. By inserting a new loaded magazine, the shooter ensures that they have a fresh source of ammunition ready for continued operation after addressing the malfunction.

Using a loaded magazine is critical because the original magazine may be malfunctioning or its rounds may be jammed, and continuing to use it could perpetuate the issue. A new loaded magazine provides both the necessary immediate ammunition supply and ensures reliability as the shooter moves forward in addressing the malfunction. It enables a faster transition back to normal operation, emphasizing the importance of quick, decisive action in high-pressure situations.