What is used as an aid to ensure the bolt is completely forward on the M4?

• A. Dust Cover
• B. Charging Handle
• C. Muzzle Brake
• D. Forward Assist

Answer: (D)

When the bolt doesn’t fully move forward to lock the chamber, the forward assist provides a manual way to complete the action. It’s a push-button on the right side of the receiver that, when pressed, drives the bolt carrier forward so the bolt seats and locks properly. This is a backup measure after loading or a misfeed to ensure the weapon is in battery and ready to fire. The dust cover just shields the ejection port and has no role in bolt movement. The charging handle is used to manually cycle the action and chamber a round, but it doesn’t specifically guarantee the bolt is fully forward on its own. The muzzle brake is for reducing recoil and doesn’t affect bolt position either.