How to Lower FPS on Airsoft Gun? A Quick Guide for Maximum Safety

In the world of airsoft guns, you likely know that FPS (feet per second) indicates the velocity at which a BB pellet travels as it exits the barrel of your airsoft gun. While having a high FPS can be fun and sometimes even necessary for certain outdoor games, there may be situations where you need to lower the FPS of your airsoft gun.

Whether you want to comply with game regulations or improve safety, learning to lower the FPS on your airsoft gun is an essential skill. In this article, we’ll discuss some methods to help you achieve a lower FPS, ensuring a more enjoyable experience for you and your fellow airsoft players.

Why Lower FPS?

Lowering the FPS (Feet Per Second) on your airsoft gun might seem counterintuitive, but doing so has several benefits. This section will cover the reasons, including Field Limits, Safety, Accuracy, and Range.

Field Limits

Most airsoft fields have strict FPS limits to ensure the safety of all players. By reducing the FPS of your gun, you can meet these requirements and participate in any field without issues. Don’t risk violating field regulations; take the time to adjust your gun’s FPS accordingly.


Higher FPS increases the potential for injuries, especially when playing in close quarters. Lowering the FPS on your airsoft gun reduces the impact energy it delivers, resulting in a safer experience for you and your fellow players. Keep everyone’s well-being in mind; a fun game doesn’t have to be dangerous.


Contrary to popular belief, a lower FPS can improve shot accuracy (but this is not always the case). High FPS airsoft guns tend to suffer from over-hop, which sends the BBs off-course. By decreasing the FPS, you can achieve more stable shots, allowing you to hit your targets with greater precision.


While a higher FPS might mean a longer range, this isn’t always the case. The range is more about the quality of your hop-up system and the weight of the BBs you’re using. Lowering the FPS allows you to use heavier BBs, which can improve the overall effective range of your gun.

Different Types of Airsoft Guns

There are three main types of airsoft guns: spring, gas, and electric (AEGs). Each type has its characteristics and ways to lower FPS, and it’s essential to know the differences and the mechanics behind them to lower FPS safely.


Spring-powered airsoft guns use a simple, manual mechanism. Cocking the gun compresses a spring that stores potential energy. When fired, the spring is released, and this energy is transferred to the BB through compressed air.

Lowering FPS in spring guns can often be accomplished by:

  • Changing the spring to a less powerful one.
  • Shortening the stock spring.
  • Installing a stronger piston with a weaker spring.


Gas-powered airsoft guns function using a gas source, typically CO2, Green Gas (propane), or HPA (High-Pressure Air). The gas stored in a reservoir, such as a magazine, is released through a valve to propel the BB forward.

To reduce FPS in gas airsoft guns, consider the following:

  • Using a lower-pressure gas or adjusting the PSI on an HPA system.
  • Installing an adjustable valve or restrictor.
  • Swapping out the inner barrel for a shorter or wider one.

Electric (AEGs)

Electric Airsoft Guns (AEGs) are powered by a battery that drives a motor. This motor, in turn, cycles internal gears to compress a spring and release it, propelling the BB forward using compressed air.

Ways to lower FPS in AEGs include:

  • Using a weaker or less-torqued motor.
  • Replacing the spring with a less powerful one.
  • Adjusting the spring guide to reduce the spring’s pre-compression.

Methods to Lower FPS

You can use a few methods to lower the FPS on your airsoft gun. This section will cover four techniques that will help improve your airsoft gun’s safety and accuracy during gameplay.

Using Heavier BBs

Switching to heavier BBs is a quick and easy way to lower your gun’s FPS. Heavier BBs travel slower than lighter ones, effectively reducing the FPS. To see the difference:

  • Experiment with 0.25g, 0.28g, or even 0.30g BBs
  • Observe the change in FPS and accuracy

Changing the Spring

Replacing the spring in your airsoft gun with a new, weaker spring can lower the FPS. To achieve this:

  • Select a spring with a lower power rating (e.g., M90, M100)
  • Consult your gun’s manual for proper disassembly and reassembly

Adjusting the Hop-Up

Optimizing the hop-up on your airsoft gun can indirectly reduce FPS while improving shot accuracy. To adjust your gun’s hop-up:

  • Access the hop-up adjustment point on your gun
  • Increase hop-up to add backspin until the desired flight path is achieved

Installing a Velocity Reducer

A velocity reducer can be installed on the barrel of your airsoft gun to lower FPS. Remember the following when using a velocity reducer:

  • Not all airsoft guns are compatible with velocity reducers
  • Installation may require professional assistance to ensure proper fit and function

Choosing the Right Parts and Materials

When attempting to lower the FPS of your airsoft gun, there are a few essential parts and materials to consider. We’ll focus on three primary components: the inner barrel, the spring, and the piston head.

Inner Barrel

Selecting the right inner barrel is essential for managing FPS. A longer inner barrel can help decrease the FPS. Also, consider switching to a wider bore barrel, as it may allow more air to escape, resulting in a lower FPS.


Your choice of springs can significantly impact the airsoft gun’s FPS. A common modification is to swap the stock spring with a lower power spring. For instance, you can replace an M110 spring with an M100 to decrease the FPS. Ensure proper installation with a compatible spring guide.

Piston Head

The piston head is another component that can affect FPS. It is responsible for compressing the air that propels the BB. Consider using a plastic piston head rather than a metal one, which can reduce air compression and lower FPS. The material plays a crucial role in determining the performance and longevity of the piston head.

Step-by-Step Guide to Modifying Your Airsoft Gun

To lower the FPS of your airsoft gun, follow these steps:

Step 1: Select the Appropriate Method

Research different methods to modify your airsoft gun. Some common options to lower power output include changing the spring or adjusting the hop-up. Make sure to choose a method compatible with your specific airsoft gun model.

Step 2: Disassemble the Gun

Refer to your airsoft gun’s user manual for disassembly instructions. Carefully remove the necessary components to access the part you need to modify.

Step 3: Perform the Modification

  1. If changing the spring, replace it with one of lower power.
  2. If adjusting the hop-up, turn the dial or lever to experiment with different settings.

Reflect to note any changes you make to revert to the original configuration if necessary.

Step 4: Reassemble and Test

Reassemble your airsoft gun following the manual’s instructions.

Always test the modified gun in a controlled environment, such as an airsoft field. Use a chronograph to measure the new FPS and ensure it is within the desired range.

Considerations and Precautions

When looking to lower the FPS (feet per second) on your airsoft gun, there are several factors you need to consider and precautions to take. This section will cover field limit compliance, power and consistency, and airsoft gun maintenance.

Field Limit Compliance

Ensuring that your airsoft gun complies with field limits in your area is vital. Some fields may have specific FPS restrictions to ensure safety and fair gameplay. Check your local airsoft field’s regulations and adjust your gun’s FPS accordingly.

Power and Consistency

Lowering the FPS of your airsoft gun can affect its power and consistency. A more powerful gun can shoot heavier BBs, increasing their range and accuracy, while a consistent gun ensures that every shot you take performs similarly. Lowering FPS may reduce power and consistency, potentially affecting your gameplay experience.

Maintaining Your Airsoft Gun

Properly maintaining your airsoft gun is crucial when adjusting its FPS. Regularly inspect your gun and its gearbox to ensure they’re in good condition. Clean and lubricate all moving parts to ensure smooth operation, and monitor the FPS to prevent it from dipping too low, which can cause malfunctions.

In summary, when considering lowering your airsoft gun’s FPS, take precautions with field limit compliance, power and consistency, and maintain your airsoft gun. By following these guidelines, you can ensure safe and enjoyable gameplay.

Additional Tips and Tricks

Barrel Length and Hop-Up Unit

Consider experimenting with barrel length to find the best performance for your airsoft gun. While a longer barrel may aid in accuracy, it doesn’t necessarily mean lower FPS. The correct balance is key.

The hop-up unit significantly affects FPS. Adjust or replace your hop-up nub and ensure your hop-up O-ring is in good condition to manage your airsoft gun’s FPS better.

Using Duster Gas

Using duster gas is a relatively easy way to decrease FPS. Duster gas, commonly found as a cleaner for electronics, has a lower pressure than standard green gas, resulting in reduced FPS. Before attempting this method, ensure your airsoft gun is compatible with duster gas.

Selecting the Right BBs

Selecting the correct BB weight is crucial to your airsoft gun’s performance. Heavier BBs are less likely to be affected by wind and maintain a consistent trajectory but may reduce FPS. Experiment with different BB weights to find the optimal balance for your desired FPS and accuracy.

Here is a quick rundown of the section:

  • Barrel Length: Determine the best balance between accuracy and FPS.
  • Hop-Up Unit: Adjust or replace the hop-up nub and O-ring for better FPS management.
  • Duster Gas: Use a lower-pressure gas to decrease FPS.
  • Selecting the Right BBs: Experiment with different BB weights for optimal performance.

Popular Airsoft Gun Models

M4 Sniper

The M4 Sniper is a popular airsoft gun model for outdoor play. Its versatile design and high FPS (feet per second) make it a top choice for accuracy and long-range engagements. To lower the FPS on your M4 Sniper, consider changing the spring to a lower power option or adjusting the hop-up system.

Here are some M4 Sniper models to consider:

  • Classic Army M24 Socom
  • ASG Steyr SSG 69 P2
  • CYMA VSR-10

Indoor Play

For indoor play, selecting an airsoft gun with a lower FPS is important to meet the safety requirements of most indoor fields. Some popular models suitable for indoor use include:

To lower the FPS on these indoor airsoft guns, switch to a lower power spring or install a Quick Change Spring System (QCSS) if available. This can help ensure safe and enjoyable gameplay in indoor environments.


Lowering the FPS on your airsoft gun can provide various benefits, such as increased safety and compatibility with different playing fields. You can achieve this through multiple methods, including spring replacements, nozzle adjustments, and a lower-power battery.

Always take safety precautions when modifying your airsoft gun and consult the manufacturer’s recommendations. Altering the FPS might affect your gun’s performance, so choose the proper method for your desired outcome.

Now that you have the knowledge and tools, fine-tune your airsoft gun to suit your playing style and preferences. Enjoy the game, and happy shooting!

Frequently Asked Questions

Q. What factors affect the FPS of an airsoft gun?

Several factors can affect your airsoft gun’s FPS (feet per second). Firstly, the strength of the spring is crucial, as a stronger spring will increase FPS while a weaker one will lower it.

Secondly, the length of the barrel can also impact the FPS, with a longer barrel generally allowing for better air compression and resulting in higher FPS.

Finally, proper seals and compression components are important in maintaining air pressure and impact FPS.

Q. How can I safely lower the FPS of my airsoft gun?

There are several steps you can take to achieve this. Installing a lower-tension spring can reduce the force behind the BBs and result in a lower FPS. Shortening the barrel with a shorter or wider one can decrease FPS by allowing air to escape more easily.

Finally, adjusting the hop-up can also impact FPS, as tuning the hop-up can affect the backspin on BBs and sometimes reduce their velocity.

Q. What should I avoid when lowering FPS?

Be cautious not to damage your gun. Don’t use materials or tools that could harm the components; avoid removing essential parts. Consult the manual and seek expert advice if you need clarification on any modifications.

Leave a Comment

Your email address will not be published. Required fields are marked *