Air rifles fire a projectile with a blast of compressed air.
Air rifles are designed to project a pellet with compressed gas (air), usually created by the release of a cocked piston under the force of a spring. Over time the spring can lose some of its tension and power, especially if it has been left in the cocked position, leaving pressure on the spring. As some air rifles are capable of firing their projectiles at speeds of up to 1,200 feet per second, the springs are too strong to be compressed by hand. To install a new spring in an air rifle, you will need a press to compress the spring and an air gun spring kit that includes a new spring, seal and lubricant.
1. Lay the air rifle alongside the spring press and turn the handle on the press until it opens far enough to accept the rifle, from the end of the stock to the tip of magazine cover (below the barrel).
2. Insert the rifle into the press and turn the handle of the press until the plate at the end of the shaft of the press contacts the magazine cover. Remove the screws on the side of the magazine cover with the screwdriver.
3. Turn the handle of the press counterclockwise, releasing pressure on the magazine cover, allowing the spring to expand and push the magazine cover off the rifle. Continue turning the press handle until all tension has been released from the spring.
4. Remove the rifle from the press and pull the spring, and the attached piston, out of the gun with your hand.
5. Hold the piston in one hand and the spring in the other and twist the spring free from the piston. Pry the rubber piston seal from its groove on the back of the piston with a screwdriver, using care not to gouge the piston. Apply gun cleaner to the cloth and wipe the spring and the piston.
6. Coat the new rubber piston seal with lubricant, working it in well with your fingers. Gently stretch the seal over the end of the piston, seating it into the groove. Apply lubricant to the cloth and coat the new spring. Twist the spring into the piston and apply a second coat of lubricant to the piston and rubber seal with the cloth.
7. Insert the piston and spring (piston first) back into the rifle and place the rifle in the press. Place the magazine cover over the end of the air rifle spring. Turn the handle of the press until the piston and spring are completely seated in the rifle, with the magazine cover in full contact with the end of the magazine. Inert the screws into the magazine cover and tighten with the screwdriver. Remove the gun from the press.