Official video workshop · 1:47
Silverback VKS hop-up nub swap
Choose between the 0, +250 µm and +500 µm VKS nubs, install the concave face toward the bucking and step down again if feeding becomes unreliable.
Before you start
Key facts and tools
| Specification | Official value |
|---|---|
| Available nubs | 0 / +250 µm / +500 µm |
| Use a taller nub when | Maximum setting 9 still gives too little hop |
| Orientation | Concave side against hop-up bucking |
| Use a lower nub when | Jamming or excessive feeding resistance appears |
Tools
- VKS pin punch
- Parts tray for the small red nub
- Clean hands or non-marring tweezers
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
Confirm the symptom
Use a taller nub only when the VKS still lacks hop effect at the maximum setting of 9.
Open the receiver
Drive out both body pins, remove the handguard and stock, place the top cover on its right side and slide out the receiver.
Remove the existing nub
Lift the small nub from its seat and place it in a tray so it cannot be lost.
Choose the next height
Select 0, +250 µm or +500 µm according to the observed hop range. Increase only as much as necessary.
Set the concave orientation
Install the nub with its concave side against the hop-up bucking. A reversed nub will not apply pressure as intended.
Return the receiver to the cover
Slide the receiver into the top cover while protecting the dust cover, then turn the top-cover assembly upside down on the rail.
Install stock and handguard
Fit the stock with the selector on FIRE, engage the trigger guard with the pistol grip and install the handguard.
Insert pins and test feeding
Long pin front and short pin rear, both by hand. If the new nub causes jams, return to a lower nub.
Critical checks
- Do not jump straight to +500 µm without testing.
- Concave face must contact the bucking.
- Protect the dust cover during receiver installation.
- Never hammer the body pins.
- Step down if feeding resistance or jams appear.
FAQ
Frequently asked questions
Which nub should I fit if setting 9 is not enough?
Move up one height from the current nub, test hop and feeding, and only increase again if necessary.
Which way does the nub face?
Its concave side faces and contacts the hop-up bucking.
What if the VKS starts jamming?
The nub may be too tall for the setup. Silverback recommends choosing a lower nub.
Share:
Silverback VKS Main Spring Swap Guide
Silverback VKS Fixed Dust Cover Setup Guide