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How to Lower the FPS of Your Airsoft Gun

How to Lower the FPS of Your Airsoft Gun

Airsoft fields and events often enforce FPS limits to ensure player safety and fair play. These limits are usually determined by the type of game, the proximity of engagements, and the protective gear used. By having control over your airsoft gun's FPS, you can comply with these airsoft FPS limits and contribute to a safe gaming environment. Throughout this guide, we will provide step-by-step instructions, tips, and precautions for modifying the airsoft FPS of different types of airsoft guns. Whether you're looking to decrease the FPS to meet field regulations or simply adjust it for specific game scenarios, we've got you covered.

We will begin by exploring techniques for lowering the FPS of AEGs, which are popular due to their reliability and ease of use. We will also dive into the intricacies of GBBRs, which offer a realistic shooting experience and HPA guns, which are known for their consistency and customization potential. By the end of this blog, you'll have the knowledge and confidence to modify the FPS of your airsoft gun while maintaining safety and adhering to field regulations. Remember, it's essential to exercise caution and follow local laws and guidelines when making adjustments to your airsoft gun.

Understanding FPS in Airsoft

In airsoft, FPS stands for Feet Per Second. It is a unit of measurement used to determine the velocity or speed at which a projectile, such as a BB (plastic pellet), is propelled from an airsoft gun. FPS is used to indicate the power and performance of an airsoft gun. It measures how fast the BB travels when it is fired from the gun's barrel. The higher the FPS, the faster the BB will travel.

FPS is an important factor in airsoft as it affects the range, accuracy, and impact of the BB. Generally, airsoft guns with higher FPS can shoot BBs farther and with more force. However, it is important to note that FPS is not the sole determinant of accuracy, as other factors such as the hop-up adjustment, barrel quality, and BB weight also play a significant role.

In many countries, including Canada, there are specific FPS limits and regulations that govern the use of airsoft guns. These limits are in place to ensure player safety and reduce the risk of serious injuries. It is important to adhere to these FPS limits and any local regulations regarding airsoft gun velocity to maintain a safe and enjoyable airsoft experience.

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How to Lower the FPS of Your Airsoft Gun

In order to effectively lower the FPS of your airsoft gun, we will break down the process into three distinct sections: AEGs, GBBR/ Gas Guns, and HPA guns. Each of these systems operates differently and requires specific adjustments to modify the airsoft FPS within the desired range. By organizing our guide into these three sections, we ensure that you receive tailored information and specific instructions for your airsoft gun's system. Remember, Opening up your gun may void its warranty, and if you lack the necessary expertise, it's best to seek assistance from a qualified airsoft technician. So, let's dive into each section of this guide and equip you with the knowledge and techniques necessary to confidently lower the FPS of your airsoft gun.

GBBR/Gas Guns:

An NPAS (Negative Pressure Air System) is a device or system used in airsoft to adjust the FPS of a gas blowback airsoft gun. It is typically found in gas-powered airsoft rifles and pistols. The NPAS allows the user to control the amount of gas that propels the BB and, consequently, the velocity or FPS of the gun. By adjusting the NPAS, you can increase or decrease the gas flow, which directly affects the power and speed at which the BB is propelled.

Typically, the NPAS system is installed within the nozzle, which is an integral component housed within the bolt or slide assembly of the gun. The nozzle acts as the conduit through which the gas is directed to propel the BB. By incorporating an adjustable screw or valve mechanism within the nozzle, the NPAS allows users to precisely control the gas flow and, consequently, regulate the velocity at which the BB is propelled.

However, it's important to note that due to the diverse range of gas blowback rifles available in the market, nozzle and bolt designs can differ significantly among various models and manufacturers. Therefore, prior to attempting any modifications, it is highly recommended to conduct thorough research to identify the specific nozzle or bolt used in your particular gas blowback rifle. This will ensure that you have a clear understanding of the NPAS system's compatibility and the correct approach to adjusting the FPS without causing any unintended issues or damage to your gun.


When it comes to adjusting the FPS of an AEG (Automatic Electric Gun), changing the spring is considered one of the most effective methods. The spring plays a crucial role in determining the power output and velocity of the BB. By selecting a spring with a different strength or rating, you can increase or decrease the FPS of your AEG to suit your specific needs and field regulations.

To change the spring in an AEG, you will typically need to disassemble the gearbox, which houses the internal components responsible for firing the BB. It's important to note that gearbox disassembly requires technical knowledge and experience, so if you're unfamiliar with the process, it's advisable to seek assistance from a qualified airsoft technician. However most airsoft AEG guns now come with quick change springs.

When selecting a new spring, it's crucial to consider several factors. First, you should determine the desired FPS range you wish to achieve. This can be influenced by field regulations or personal preferences. Additionally, it's important to consider the compatibility of the spring with your AEG gearbox. Different gearbox designs may require specific spring lengths or strengths to ensure proper function and reliability. Most stock AEG’s will come with an M120 or M110 spring installed so changing to M100 or M90 will be perfect for CQB.

It's worth noting that changing the spring alone may not be the only adjustment required to optimize your AEG's performance. Other components, such as the air nozzle, cylinder, and hop-up unit, may also need to be considered for achieving desired FPS and overall efficiency.


When it comes to HPA (High-Pressure Air) airsoft guns, adjusting the FPS can be achieved through various methods. HPA guns offer greater flexibility in adjusting FPS due to their pneumatic system. To lower the FPS of an HPA airsoft gun, there are several techniques you can employ. First, you can adjust the regulator's output pressure to decrease the force with which the BB is propelled. Another method is to modify the dwell setting, which controls the duration of time the solenoid valve stays open, thus decreasing the air released per shot.

Some HPA guns may also offer the option of installing air restrictors to reduce air flow and lower FPS. It is important to note that after making adjustments, chronographing the gun is essential to ensure compliance with field regulations. Always follow manufacturer guidelines and consult an experienced technician if you are unsure about any modifications.

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Why Do Airsoft Fields Have an FPS Limit?

Airsoft fields implement FPS airsoft limits for several crucial reasons. The foremost concern is safety, as exceeding certain FPS limits can lead to serious injuries. By enforcing these limits, fields aim to reduce the risk of harm to players, such as eye injuries or excessive bruising. Additionally, FPS limits promote fairness and balance among players by ensuring that everyone operates within a standardized level of power, preventing unfair advantages.

Moreover, these limits help protect players' equipment by minimizing stress on internal components and reducing the likelihood of malfunctions or breakages. Furthermore, FPS limits contribute to the integrity of the field itself, preventing excessive damage to structures and props while maintaining a consistent playing environment. By adhering to FPS limits, airsoft fields prioritize safety, fairness, equipment protection, and the overall integrity of the game.

Final Remarks

In conclusion, FPS limits play a vital role in the world of airsoft. They serve as a cornerstone of safety, ensuring that players can engage in the sport without undue risk of injury. By promoting fairness, FPS limits create an equal and enjoyable playing field for all participants. They also safeguard the longevity and performance of airsoft equipment, minimizing the potential for damage and malfunctions. Ultimately, FPS limits are a crucial aspect of responsible airsoft gameplay, fostering a safe, fair, and sustainable environment for enthusiasts to immerse themselves in this thrilling sport.

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