What are the categories of malfunctions for the M4 rifle?

• A. Failure to feed, chamber or lock; Failure to fire cartridge; Failure to Extract; Failure to Eject
• B. Failure to feed; Failure to eject; Failure to lock; Failure to fire
• C. Failure to feed; Failure to eject; Failure to lock; Failure to fire
• D. Failure to chamber; Failure to cycle; Failure to feed; Failure to eject

Answer: (A)

The main idea is to categorize malfunctions by where in the rifle’s firing cycle the problem occurs. There are four common failure points: feeding/chambering/locking, firing, extraction, and ejection. If the weapon fails to feed, chamber, or lock, the round never properly enters the chamber or the bolt won’t lock, so the cycle stops before firing. If the primer fails to ignite, the round won’t fire. If the cartridge can’t be extracted, it remains in the chamber and blocks the cycle. If the spent case isn’t ejected, a jam can occur and prevent subsequent cycles. This four-category approach matches the full set of failure modes in a practical repair-and-troubleshoot framework, which is why it’s considered the correct grouping. The other options either omit one of these stages or treat a nonstandard or redundant term as a separate category, which doesn’t align with how malfunctions are organized during operation and troubleshooting.