Final answer:
The statement is true; the counter-recoil phase is initiated by the rapidly expanding gases produced when a bullet is fired, consistent with Newton's third law of motion.
Step-by-step explanation:
The counter-recoil phase is indeed initiated by the rapidly expanding gases generated as a bullet is being fired, making the statement true. When a bullet is fired from a gun, the powder within the cartridge ignites and generates high-pressure gases. These gases expand rapidly, pushing the bullet out of the barrel. According to Newton's third law of motion, every action has an equal and opposite reaction; therefore, as the bullet is propelled forward, the gun is pushed backward, which is experienced as recoil. This is why firearms have mechanisms to manage this force and why it is important to handle them correctly to ensure safety.