When should headspace adjustments be checked on the M240?

Headspace adjustments are crucial for the safe and proper functioning of the M240 machine gun, particularly because changes in the weapon's components can affect how well the ammunition seats and fires. Regularly checking headspace ensures that the chamber dimensions remain within the required specifications, thereby preventing potential malfunctions or safety hazards.

When major components such as the barrel or bolt assembly are replaced, the headspace may be altered, making it necessary to verify and, if needed, adjust it. This practice helps maintain the reliability and accuracy of the weapon. Additionally, periodic checks can account for wear and tear that may occur over time, ensuring the weapon remains in optimal condition. Thus, monitoring headspace not only promotes safety but also ensures the operational effectiveness of the M240.