What common stoppage is characterized by a double feed?

A double feed is characterized by a situation where two rounds are trying to enter the chamber at the same time. This typically occurs when one round remains in the chamber while another round is fed from the magazine. The correct answer identifies how an obstruction can prevent the proper functioning of the rifle.

When brass or spent casings obstruct the chamber area, it can prevent the bolt from fully seating the next round, creating a scenario where a second round is fed into the chamber or the feed lips of the magazine. This obstruction can lead to a double feed, as the rifle's cycling continues, but the chamber is cannot accommodate another round due to the presence of the spent casing or other debris.

Understanding this stoppage helps in diagnosing issues with rifle malfunctions and knowing how to clear them effectively during training or real-life scenarios. Familiarization with the mechanics of the firearm, including the potential for obstructions in the chamber, is crucial for maintaining operational readiness and ensuring effective response during qualifications and when using the rifle in the field.