Official video workshop · 4:51
Fit an SRS outer barrel to the Silverback VKS
The official SRS-barrel conversion: FAST hop requirement, 4 Nm receiver torque, optional VKS rail cover and clockwise/counter-clockwise hop adjustment.
Before you start
Key facts and tools
| Specification | Official value |
|---|---|
| Compatibility | SRS outer barrel must use a FAST hop-up |
| Barrel clamps | 4 Nm |
| Optional cosmetic step | Remove hop wheel and ball plunger; fit supplied cover |
| FAST adjustment | Clockwise increases hop; counter-clockwise decreases |
Tools
- Pin punch
- Correct drivers for barrel and rail screws
- Torque wrench capable of 4 Nm
- Silverback printable FAST adjustment tool (recommended)
Primary source
Watch the official Silverback tutorial
This guide follows the official subtitles and footage. Use the video for hand position and the written text for measurements, orientation and checks.
Procedure frames
Procedure
Step by step
Remove the furniture
Drive out both pins, remove the handguard and stock, then loosen the four barrel-clamping screws.
Separate receiver and barrel
Slide the receiver from the top cover, remove the nub, drive out the barrel-lock pin and pull the VKS barrel from the receiver.
Confirm FAST hop compatibility
Before installation, verify that the SRS outer barrel is equipped with a Silverback FAST hop-up chamber.
Insert and lock the SRS barrel
Slide the SRS barrel into the VKS receiver in the correct orientation, reinstall the barrel-lock pin and tighten all four clamps to 4 Nm.
Choose wheel or cover
The VKS can be reassembled with the FAST wheel present. For a cleaner exterior, remove the three rail screws, the hop wheel and its ball plunger, then slide in the supplied cover.
Refit the top rail
Reinstall the three rail-mounting screws, then slide the receiver into the top cover while protecting the dust-cover mechanism.
Install stock, handguard and pins
Put the assembly upside down on the rail, fit the stock with the selector on FIRE, then the handguard. Long pin front, short pin rear, both by hand without a hammer.
Adjust the FAST hop
Use the printable adjustment tool recommended in the video. Turn clockwise to increase hop effect and counter-clockwise to reduce it.
Critical checks
- Do not install an SRS barrel without FAST hop.
- Reinstall the barrel-lock pin before torqueing.
- Use 4 Nm on the four clamps.
- Do not lose the ball plunger when removing the wheel.
- Long pin front; short pin rear; no hammer.
FAQ
Frequently asked questions
Can any SRS outer barrel be fitted to the VKS?
No. The official tutorial requires the SRS barrel to be equipped with a FAST hop-up.
What torque is used on the VKS barrel clamps?
Tighten the four receiver clamping screws to 4 Nm.
Which way increases FAST hop?
Clockwise increases the hop effect; counter-clockwise decreases it.
Share:
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