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ASG Ultimate AEG Spring

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$8.99 - $11.99

Free Shipping on Orders $200 or More ($9.99 for orders under $200)

Fox Airsoft offers a 30 day warranty and return policy.

Action Sport Games brings us another line of high quality upgrade part from their Ultimate series. These are the ASG Mil-Spec AEG Springs. These are high quality springs designed to deliver consistent performance. These springs are made from firearm grade steel for the best durability and lifespan.

Ratings available are from M95 up to M135. Springs are color-coded for easy identification. All springs are calibrated and tested at the factory and specifications are delivered from a test gun with a 300mm 6.03mm tight bore barrel, volume matched cylinder, and 0.20g BB's with zero hopup engagement. Your final FPS will vary based on your parts used. Professional installation is recommended. No returns on springs.

Springs - made from mil-spec steel - silicon chromium (SiCr). Springs made from cheaper materials that are not treated fatigue sooner rather than later or can possibly snap. A snapped spring can lock up your gearbox, damage other parts, give you low FPS.

Progressive coils - gives your gears a soft start which eases stress on mechanical and electrical components. Typically springs that are linear do the opposite. You might not notice this but efficiency will be further enhanced by going with a progressive coil spring.

Closed flat ends - prevents alignment issues and flexing assosciated with cut springs which reduces rate-of-fire or can cause other cycling problems.

Pre-compressed - extra lengthy spring means less tension loss after initial install. Springs can "settle" shortly after install giving you lower fps than your initial expectation. Warning: these springs are longer than competing brands and might be difficult to install for amateur techs.

Black zinc plating - extra corrosion protection which could compromise the springs integrity if rusted.


  • Blue = M95, Springrate 0.447N/mm ~300-320fps w/0.20g
  • Green = M105, Springrate 0.467N/mm ~340-360fps w/0.20g
  • Yellow = M115, Springrate 0.519N/mm ~370-390fps w/0.20g
  • Orange = M125, Springrate 0.826N/mm ~400-420fps w/0.20g
  • Red = M135, Springrate 0.943N/mm ~ 435-455fps w/0.20g

For players with gearboxes that allow for quick spring changes, you can always carry with you extra springs to adjust your AEG for indoor and outdoor play (*please use this feature responsibly). Keep in mind that on these guns, changing the spring may be easy but not always appropriate for your otherwise stock gun. Jumping up from a stock gun that shoots 380-400fps with a spring that is easily 2 ratings over will put more wear and tear as well as stress on your components including the piston, gears, and motor. Downgrading your spring to a weaker one will also have an adverse effect if you do not understand what you are doing. A weaker spring lowers your FPS but with less load on your motor your gun will likely gain a slight boost in rate of fire. If you are unsure about what you should or should not use, feel free to contact us with questions by calling us at (888)316-7816 or e-mailing

If you do not have a quick change system for your AEG, you will have to seek a professional tech to have your gun upgraded or downgraded.

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