RetroArms AEG Spring SiCr with Progressive Wiring – M130

RetroArms AEG SiCr progressive spring

RetroArms AEG spring is designed for standard AEG gearboxes and is one of the key components affecting the resulting performance of an airsoft gun. It is made from silicon-chromium (SiCr) alloy valve spring wire, selected by RetroArms with long-term retention of the spring's mechanical properties in mind. According to the manufacturer, the spring retains its stiffness even after several thousand shots without unwanted deformation. Progressive or variable winding makes compression easier during the initial stage of piston movement, while the more tightly wound section of the spring must be oriented towards the spring guide during installation. This section is also colour-coded according to the spring rating. The spring has an outer diameter of 14.5 mm. The spring rating is an approximate indication of spring strength; actual muzzle velocity and energy always also depend on the air seal, barrel length and diameter, cylinder used and other parameters of the specific build.

RetroArms spring ratings and colour coding

RetroArms springs are colour-coded for easy identification of individual ratings. The M designation indicates the approximate velocity the spring may achieve with a 0.20 g BB in a conventional, properly sealed build. Actual performance is also affected by air seal, cylinder volume, barrel length and diameter, hop-up bucking, weight of moving components and the overall tuning of the gun. The performance and range values in the table are therefore approximate and not guaranteed.

*Note on range: The stated theoretical maximum range does not represent the distance at which the gun will accurately and consistently hit a target. In practice, usable range is significantly affected by the quality and adjustment of the hop-up system, suitable BB weight, performance consistency, barrel and weather conditions. Higher power therefore does not automatically result in a proportionally longer or more accurate range.

Technical specifications

• Type: AEG spring with progressive winding
• Rating: M130
• Material: Silicon-chromium (SiCr) alloy valve spring wire
• Winding: Progressive (variable)
• Outer diameter: 14.5 mm
• Design: Standard length for AEG gearboxes

Package contents

• 1× RetroArms AEG SiCr progressive spring (M130)

Installation

When installing a spring with progressive winding, the compressed part (where the coils are closer together) goes on the spring guide. RetroArms marked this spot with color for easy identification of the spring strength.

Frequently asked questions (FAQ)

How should a progressive spring be oriented correctly?

The tightly wound section with the coils positioned closer together should face the spring guide. On this version, it is also marked in yellow, making the M100 spring easy to identify.

Is this spring suitable for SR25 or Tokyo Marui NGRS?

No, this version has a standard length for conventional AEG gearboxes. RetroArms offers separate spring types for extended SR25 / PSG gearboxes and shortened Tokyo Marui NGRS systems.

What does progressive spring winding mean?

The coils are not spaced at the same intervals along the entire length of the spring. According to the manufacturer, this variable winding makes the spring easier to compress during the initial stage of piston movement, while the tightly wound section must be correctly oriented towards the spring guide during installation.