Silverback 13mm 120N Spring – APS Standard SRS/TAC-41

The Silverback 13mm 120N spring is a precision replacement and upgrade component for serious bolt-action builders and players running SRS or TAC-41 platforms. Built to the APS 13mm standard, this spring guarantees compatibility with any rifle fitted with a 9mm O.D. spring guide—covering all current SRS models and TAC-41 variants.

Key Features

• APS 13mm standard – fits SRS and TAC-41 rifles without modification
• 120 Newton output (±5%) – approximately 9 kg of spring force for consistent velocity
• Compressed length 99mm – optimised for standard guide geometry
• Black electrophoresis finish – corrosion-resistant and professional appearance
• Precision engineering – ensures smooth cycling and reliable performance over thousands of shots

Real-World Use Cases

This spring is essential for upgrading your SRS or TAC-41 to a higher power tier, or replacing a worn unit. At 120N, it sits in the mid-range for bolt-action performance—ideal for outdoor skirmish and milsim events where velocity caps typically allow 500+ fps with 0.20g BBs. Builders chasing specific chronograph targets will find this a reliable, predictable foundation.

Technical Specifications

• Standard: APS 13mm (9mm O.D. spring guide)
• Spring Force: 120 Newtons (±5%)
• Compressed Length: 99mm
• Finish: Black electrophoresis
• Compatibility: SRS (all current models), TAC-41

Compatibility & Upgrades

The Silverback 13mm 120N spring is a direct swap for any APS-standard spring guide. Use it as a like-for-like replacement, or combine with upgraded cylinders, pistons, or airseal components to fine-tune your bolt-action’s performance envelope. Pair with quality BB’s and a well-tuned hop-up for best grouping consistency.

UK Legal & Site Notes

Spring strength alone does not determine legality; your rifle’s final FPS is what matters. Always chrono your build with the ammunition supplied or specified by your local site before game day. Most UK outdoor venues permit bolt-action rifles up to 500 fps on 0.20g (roughly 2.3 joules); check your site’s rules. This spring is a component only and is not subject to UKARA licensing.

Invest in a reliable, precision spring from Silverback and enjoy consistent, predictable velocity in your SRS or TAC-41. Order now from Airsoftdirect UK.