What should always be verified before using the M240B?

The functionality of the anti-reflection device is crucial to verify before using the M240B because it helps prevent glare and reflections that could compromise the operator's position and stealth. This device is especially important in combat situations where maintaining a low profile is essential. Ensuring that the device is functioning properly allows the gunner to operate the weapon without compromising their location to the enemy, thereby enhancing the effectiveness of the weapon system in varied environments. Checking this aspect ensures that the operator can engage targets effectively while remaining less detectable.

While other factors, such as the cleanliness of the barrel, proper seating of the ammunition, and accuracy of the sights, are also important for the safe operation and effective performance of the M240B, the anti-reflection device plays a unique role in operational effectiveness and survivability in tactical scenarios.