What should you do after chambering and locking a round in double feed remedial action?

After successfully chambering and locking a round during double feed remedial action, performing a functions check is critical. This step ensures that the weapon operates correctly and safely before attempting to fire it. A functions check involves cycling the action and verifying that all mechanical parts of the weapon are working as they should—this includes checking the trigger, safety mechanisms, and the magazine release.

This process is essential because double feed scenarios can sometimes indicate a misalignment or malfunction within the firearm. By conducting a functions check, a shooter can confirm the reliability of their weapon and identify any further issues that may need addressing before engaging in live fire or training drills.

The other options, while they seem practical, do not address the immediate need to ensure the weapon is functioning properly and safely after such a malfunction has occurred. For instance, test firing could lead to an unsafe situation if the function isn’t checked first. Reinserting the magazine or clearing the weapon again without confirming functionality also doesn't address potential issues stemming from the double feed incident. Thus, performing a functions check is the most prudent and responsible course of action following remedial measures for a double feed situation.