How Do Air Rifles Work?

Air rifles are great for both beginners and experts alike. Like other firearms, they have internal and external mechanisms that allow them to operate.

Air Rifle Internal Mechanics

There are different types of air rifles available, each with unique ways of propelling rounds down range. These include:

  • Spring-piston
  • Pneumatic (PCP)
  • C02
  • Single-stroke
  • Hand Pump
  • Electric

Spring Piston Air Rifle Mechanics

A spring piston air rifle works using a coiled steel spring inside a compression chamber, which is located in the gun’s stock. When the shooter cocks the rifle, the spring is compressed, and stored energy is generated. When the trigger is pulled, the compressed spring rapidly expands and pushes a piston, which compresses the air inside the chamber and forces it out of the barrel in the form of a pellet. The expanding air creates pressure which propels the pellet out of the gun.

This type of air rifle is commonly used for target shooting and small game hunting and is considered a classic design for air guns. One advantage of spring piston air rifles is their reliability, as they don’t require any batteries or electricity to operate.

Spring piston air rifles are a great choice for beginners. For more, see our post The Best Air Rifles For Beginners.

Pneumatic (PCP) Air Rifle Mechanics

A pre-charged pneumatic (PCP) air rifle works on the principle of compressed air. They have a large air reservoir that is filled, usually using a high-pressure pump or a scuba tank. Once the air reservoir is filled, the shooter can take multiple shots without having to pump the gun before each shot.

This makes PCP air rifles convenient to use and allows for more accurate shooting, as the shooter doesn’t have to worry about pumping the gun between shots.

However, PCP air rifles are more expensive than hand pump air rifles and require more maintenance, such as regular checking of the air pressure and regular cleaning to ensure that the gun operates effectively.

C02 Air Rifle Mechanics

A CO2 air rifle works using compressed carbon dioxide (CO2) gas. The gun has a small cylinder of CO2, which is usually inserted into the stock of the gun. When the shooter pulls the trigger, a valve in the gun opens, allowing some of the compressed CO2 gas to escape and propel the pellet out of the barrel.

CO2 air rifles are known for their convenience and ease of use, as the CO2 cylinder is easily replaceable and widely available. They are also relatively accurate and can be used for target shooting and small game hunting.

However, the power of the shot can be affected by the temperature, as the pressure of the CO2 gas decreases as the temperature drops. This can result in a decrease in velocity and accuracy, making CO2 air rifles less suitable for use in cold weather.

In addition, CO2 air rifles are often more expensive than spring piston air rifles and less powerful than pneumatic air rifles. They are also more limited in terms of the number of shots that can be taken before the CO2 cylinder needs to be replaced, which can be inconvenient for extended shooting sessions.

Overall, CO2 air rifles are a good choice for those looking for a convenient and easy-to-use air rifle for target shooting and small game hunting.

Single-Stroke Pneumatic Air Rifle Mechanics

Single-stroke pneumatic air rifles use a single pump action to compress air into a chamber, which is then used to propel the pellet out of the barrel.

These air rifles are also known as ‘break-barrel’ or ‘single-pump’ air rifles. Pump or break-barrel air rifles are reloaded using manual effort. Break-barrel guns work by bending the hinged barrel down which cocks the gun.

When the air rifle is pumped or cocked, the internal air reservoir is refilled or the spring is locked and it releases when the trigger is pulled. The spring compresses air in front of it, sending the pellet or bb out of the barrel at high speed.

Hand Pump Air Rifle Mechanics

A hand pump air rifle is a type of pneumatic air rifle that uses a manual pump to compress air into a chamber, which is then used to propel the pellet out of the barrel. The shooter pumps the gun several times before each shot to build up pressure in the chamber, which is then released when the trigger is pulled.

Hand pump air rifles are similar to single-stroke pneumatic air rifles in terms of operation but with the added benefit of being able to adjust the pressure in the chamber for more precise shots. They are also more environmentally friendly than CO2 air rifles, as they don’t require any disposable cylinders of gas.

A fixed barrel air rifle can have an additional lever (over lever or underlever) that is used to manually pump the gun, either once or multiple times. They are generally less expensive than pre-charged pneumatic (PCP) air rifles and CO2 air rifles, but they also require more physical effort to operate, as the shooter has to pump the gun before each shot.

Electric Air Rifle Mechanics

An electric air rifle is a type of air rifle that uses an electric motor to compress air into a chamber, which is then used to propel the pellet out of the barrel. Unlike other types of air rifles, which rely on manual pumping or disposable gas cylinders, electric air rifles use rechargeable batteries to power the electric motor.

When the shooter pulls the trigger, the electric motor quickly compresses air into the chamber, which then propels the pellet out of the barrel. This type of air rifle is often faster and more consistent than other types of air rifles, as the pressure in the chamber is more consistent with each shot. This can result in better accuracy.

However, electric air rifles are often more expensive than other types of air rifles and may be less powerful, as the batteries may not have enough power to compress the air to the same level as manual pumping or gas cylinders. In addition, they may be less reliable, as the batteries may need to be recharged or replaced, and the electric motor may malfunction over time.

Air Rifle Trigger Mechanisms

The trigger mechanism is one of the most important parts of an air rifle, as it determines how easily and accurately the shooter can fire the gun. In general, there are two main types of trigger mechanisms used in air rifles: manual triggers and automatic triggers.

  • Manual triggers are the most common type of trigger mechanism used in air rifles. They require the shooter to manually pull the trigger, which allows the air or CO2 to be released from the chamber, propelling the pellet out of the barrel. Manual triggers can be adjusted to change the amount of pressure required to pull the trigger, which can affect the accuracy and precision of the shot.
  • Automatic triggers are a type of trigger mechanism that uses an electric motor to compress the air in the chamber, allowing the shooter to fire the gun more quickly and easily. This type of trigger mechanism is typically found in electric air rifles, as it requires a power source to operate.

In addition to manual and automatic triggers, some air rifles may also have additional features, such as two-stage triggers, which have a first stage that requires a light pull to prepare the gun for firing, and a second stage that requires a heavier pull to fire the gun. This type of trigger mechanism can provide additional control and accuracy, as the shooter can take the time to aim and prepare for the shot before firing the gun.

It’s important to choose an air rifle with a trigger mechanism that is suitable for the intended use of the gun, as well as the individual shooter’s preferences and skill level.

Air Rifle Safety Switch

Similar to other firearms, air rifles include a safety switch, which serves to keep the user and anyone around them from accidental discharge.

This type of mechanism typically consists of a small switch or button that must be pressed with a thumb or other finger before the trigger can be pulled. This ensures that the gun cannot be fired unless the shooter intentionally engages the safety. If the safety is on, the gun will not fire. Safety switches are especially important for inexperienced shooters.

Semi-automatic air rifles do not need to have the safety removed for each round fired after the first one as long as the trigger is squeezed.

Do not use an air rifle that does not include a safety switch or has one that is not functioning properly. Also, if children use the gun, make sure they know how to use it. And make sure to always have the safety button set to “On” when not shooting.

Air Rifle Sights

Air rifles come with simple sights attached to the end of the barrel and the top of the main body. They can also have a scope (telescopic sight) attached. Air guns need to have their sights match the target that the gun is aimed at. The process is called ‘sighting in.’

When sighting in open sights, the rear and front sites need to be lined up and the pellet or BB is sent toward the target. If the round hits the target when the sites are aligned, then the gun is sighted in.

Scopes also need to be sighted in, and this happens after they are firmly attached to the gun and a few test shots are fired downrange. Adjusting the scope requires manually rotating the adjusters on the top or sides of the scope.

Which is Better – Open Sights or Scopes?

Open sights are included with all air rifles in the kit when purchased. They do not require expensive attachments or tools to set up and they are also fairly easy to sight in. Open sites can be used by kids.

Scopes have some advantages over open sights, the primary of which is the magnification of the target, allowing the shooter to see those farther away with more clarity. However, scopes are more delicate than open sights and can easily be damaged if the gun is dropped or bumped. Adding a scope to an air rifle is not advised for kids.

What Affects Air Rifle Velocity?

Air rifles shoot pellets at high velocity due to their mechanics and basic physics. Compressed air is filled with molecules and heat that produce kinetic energy when released. The more stored air pressure the rifle contains, the more power it will produce. However, some air rifles do not operate well below a certain temperature due to the stored gas becoming too cold.

The more power and velocity an air rifle has, the louder it likely is. So there is a tradeoff between velocity and noise — particularly for backyard suburban shooting.

Pellet size and shape also affect air rifle velocity. Heavier pellets or BBs will require more energy to send them down the barrel. And pointed pellets will travel faster and farther than round or flat-headed pellets.

For information about what makes air rifles quiet, see our post The Quietest Air Rifles.

To Close

Air rifles can provide both fun and function for adults and kids alike. However, since they are firearms, they can be dangerous if not used safely. Make sure to follow proper air rifle handling recommendations and the gun laws of your town, city, or state.

Lawrence the Airgun Ranger