What device holds the ball rotor of the 30 mm M505A3 impact fuze in an unarmed position until it is fired?

• A. Lock ring
• B. Ball bearing
• C. Safety pin
• D. Release lever

Answer: (A)

The lock ring is the critical component that holds the ball rotor of the 30 mm M505A3 impact fuze in an unarmed position until the moment of firing. By design, the lock ring ensures that the ball rotor does not move unintentionally, thereby preventing any premature activation of the fuze. This safety feature is essential for maintaining the stability and reliability of the fuze until it is intended to be launched.

When the munition is fired, the mechanism is actuated to release the lock ring, allowing the ball rotor to rotate freely, which is necessary for the functioning of the fuze upon impact. The role of the lock ring in keeping the fuze in a safe state highlights its importance in munitions safety protocols, ensuring that the device remains inert until it is purposefully activated.

The other components, such as the ball bearing, safety pin, and release lever, play different roles in the overall fuze mechanism, but it is the lock ring that specifically secures the ball rotor prior to firing, which is why it is the correct choice in this context.