RetroArms NGRS Spring SiCr with Progressive Wiring – M140

RetroArms NGRS SiCr progressive spring

This expert product description was prepared by the ANAREUS.cz expert team. All rights to this unique content are bound to the anareus.cz domain.RetroArms NGRS spring is specially designed for Tokyo Marui Next Generation Recoil Shock (NGRS / SRE) gearboxes and, compared with springs for standard AEGs, features a corresponding shortened design and an outer diameter of 13.75 mm. It is made from silicon-chromium (SiCr) alloy valve spring wire, which, according to the manufacturer, retains its stiffness and shape even after several thousand shots. Progressive or variable winding makes compression easier during the initial stage of piston movement. During installation, the tightly wound section of the spring should face the spring guide. The manufacturer guarantees compatibility only with TM NGRS gearboxes. Dimensionally, the spring also corresponds to springs used in the VFC Umarex MP7 AEG and LCT QM Series, but RetroArms does not guarantee its compatibility with these systems. The spring is not designed for conventional AEG gearboxes. The resulting performance of the build cannot be determined solely by the spring rating, as it is also affected by the air seal, barrel and other components of the specific gun.

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: Spring for Tokyo Marui NGRS
• Rating: M140
• Material: Silicon-chromium (SiCr) alloy valve spring wire
• Winding: Progressive (variable)
• Design: Shortened for NGRS
• Outer diameter: 13.75 mm
• Guaranteed compatibility: Tokyo Marui Next Generation Recoil Shock (NGRS / SRE)
• Dimensional compatibility: VFC Umarex MP7 AEG and LCT QM Series – compatibility is not guaranteed by the manufacturer

Package contents

• 1× RetroArms NGRS SiCr progressive spring (M140)

Installation

When installing a progressive spring, the tightly wound section (where the coils are positioned closer together) should face the spring guide. RetroArms marks this section with a colour for easy identification of the spring rating.

Frequently asked questions (FAQ)

Is the spring compatible with a conventional AEG gearbox?

No. This version is specifically shortened for Tokyo Marui NGRS gearboxes and is not intended as a replacement for a standard AEG spring. RetroArms offers a separate range of springs for conventional AEG gearboxes.

How should the progressive spring be oriented during installation?

The tightly wound section with the coils positioned closer together should face the spring guide.

Can the spring be used in a VFC Umarex MP7 AEG or LCT QM?

According to the manufacturer, the spring dimensions also correspond to springs used in the VFC Umarex MP7 AEG and LCT QM. However, RetroArms guarantees compatibility only with Tokyo Marui NGRS, so use in other systems is not covered by a compatibility guarantee.