In the last few years, there has been a shift in types of air rifles that are widely used in hunting and pest control. Today, the break action is much more popular than any other type of airgun for these uses. Long popular in Europe, the break action rifle is powered by moving a piston located in the receiver to the rear as the hinged barrel is pulled downward. The piston moves to the rear against a strong spring and is locked in position by the sear. When the rifle is fired, the piston is pushed forward at high velocity to compress the air in the chamber ahead of the cylinder. This air under high pressure is restricted so that it can flow out of the chamber only against the base of the pellet which forces the pellet down the barrel. Because the spring in a break action rifle is so strong, a considerable amount of force is required to cock the rifle. Although the high velocity sounds appealing, it is not without disadvantages associated with a heavy piston and spring lurching forward as the pellet is being driven out of the barrel, making it difficult to shoot such a powerful gun accurately.