Why do I need to tune my airgun?
Tune your airgun to its greatest potential.
If you are starting your air gunning journey, then one of the most challenging tasks will be to tune your airgun to its greatest potential. Everyone is looking for the tightest groups and the longest hits when going out there to shoot. To achieve this, you need to know how to adjust your airgun setup for the best results or, as we call it, “tuning.”
Tuning your airgun can be challenging and frustrating if you do not know the basics or the science behind it. A pellet or a slug leaving the muzzle of an airgun needs a specific speed and harmony to fly true and straight to its target. Shooting a projectile too fast or too slow can cause it to destabilize during flight and lead to low accuracy and consistency. FX Airguns are built around the perfect balance of pellet and slug speeds, giving their range of airguns the edge when it comes down to accuracy and long-range shooting abilities.
What do I need to tune my airgun?
The first and most important thing is to work in a safe environment suited for airgun shooting, such as a shooting range. You will need proper shooting equipment and tools to make your tuning session easier. An accurate chronograph is a must if you are serious about dialing in your airgun to its fullest potential. The FX Pocket Chronograph is small and compact with super-accurate readings via the doppler effect.
For most airguns, an Allen key set and a screwdriver set are suitable. Ensure good quality toolsets because you do not want to strip any screws and turn a tuning session into a fixing session.
You will need a large amount of air to fill up your airgun in between shot strings. We strongly suggest getting a scuba tank with a filling station to speed up the process between shot strings.
You will need a large number of pellets or slugs to tune your airgun to its best potential. Achieving that perfect accuracy sometimes requires many shots being fired on paper or over the chronograph, so be sure not to run out of ammo before working towards your goal.
Good pellet velocity data
To start tuning for pellets, you need to know some necessary information about them. Pellets are drag stabilized, and do not depend very much on spin. That said, the correct air balance is still needed to push a pellet out of the muzzle. Any extra air behind the pellet at the muzzle can give you accuracy issues.
A safe and proven speed range for shooting a pellet is between 850 fps and 910 fps. This a good starting guideline for any FX Airgun of any caliber. The FX Airguns range is designed around the JSB pellet range, and you will find top-notch accuracy out of this pellet range. You can also experiment with lower and higher speeds if you feel the need.
The first step is to test your current pellet velocity out of your airgun. Ensure you have enough air in your rifle before starting this test, and make sure you are above-set regulator pressure. Load up your magazine with your desired pellet and start shooting over the chronograph. Make sure you shoot at least 5 to 10 shots to get a good average speed.
If your pellet’s speed is below or above the desired speed, adjustments need to be made to the airgun (tuning). There are three ways of adjusting your airgun to increase or decrease pellet velocities.
You can start with the hammer spring tension. Increasing the speed means improving your hammer spring tension, while decreasing the speed denotes reducing the hammer spring tension. The latest FX range of airguns has a power wheel that you can turn to either increase or decrease tension on the hammer spring. For example, some of the airguns, such as the Dreamline classic, have a hammer spring tension screw located at the back of the action and can be externally adjusted with an Allen key. To increase the speed, turn the set screw clockwise, and to decrease the speed, turn the set screw counterclockwise.
The second way of adjustment is your transfer port. Some airgun models like the Crown and Dreamline classic have a transfer port wheel that you can turn to open up the port or close it down. The wider the transfer port’s opening, the faster the air will flow to increase the pellet’s speed. To decrease the speed, you can close the transfer port, which will slow down air. The “Min” setting is made to decelerate airflow, while the “25/30” setting maximizes airflow to increase velocities. You also have the “177/22” setting for medium airflow.
The third way of adjustment is setting your regulator pressure. Use this method if you cannot achieve the desired speed with hammer spring adjustments and transfer port adjustments. The latest airguns from FX have an external adjustment screw to calibrate the regulator from the outside without taking the airgun apart or degassing the gun. To increase the speed, you can elevate the regulator pressure, and to decrease the speed, you can lessen the regulator pressure. If you reduce the regulator pressure, then do small quarter turns at a time, and after each adjustment, dry fir the airgun three times to cycle the airflow to the regulator. Be cautious when making adjustments. If you have too much regulator pressure and too little hammer spring tension, you will lose velocity. It is crucial to maintain the balance between hammer spring tension and regulator pressure.
When the desired velocity is achieved
If you reach your desired pellet speed, you can shoot a few groups to test if accuracy is up to standard. You can achieve great accuracy with this standard method. If you tune your gun to various speeds of 20fps increments between velocities, you will find that “perfect harmonic tune” that will give you above average accuracy. This perfect harmonic tune is what most air gunners look for to achieve the best accuracy with the maximum amount of shot count. After you are satisfied with your new tuned gun setup, recheck your speed after a week of shooting. PCP airguns have settled in the period to stabilize themselves in airflow and reg pressures after a new tune has been made.
Never be afraid to experiment with different pellets and other velocities. Finding your airgun’s harmonic tune can be very rewarding and give you that confidence when you pull the trigger on your next target!