Many factory rifle scope base mounting screws are misaligned in relation to the bolt and barrel axis. This can cause windage or elevation issues, especially at long distance. The threads can also become damaged from poor fitting, recoil, poor quality screws etc.
We can upgrade your scope base or picatinny rail screws from 6-48 to a larger 8-40 or M4 thread and ensure alignment with your bolt and barrel. This is done by axially aligning the action in our Haas 4 Axis CNC mill. Once the action is aligned the new holes are helically bored using a carbide end mill. This ensures the old misaligned threads do not influence the new ones. The new threads are then thread milled- not tapped, and thread gauged to check correct specifications.
We are also able to offer damaged/broken screw removal. It is not uncommon for the small factory screws to strip, shear or break. In some cases it is possible to drill out or helically bore away the old screw and repair the threads.
Scope base screw upgrade- £120
Broken screw removal- from £40
Please note- it is not always possible to remove broken screws and may require upgrading to the larger size. Scope base screw upgrade usually requires the barrel to be removed, this may result in superficial damage to the finish.
The action is dialed in and axially aligned to the bolt raceway.
The old threads are helically bored true to the action centre line. Then the new threads are thread milled.
Checking the threads with gauges to ensure they are within tolerance.
The broken screws are accurately aligned and then drilled or bored out.
Remnants of the old screws are removed.
A tap is used to clean up and repair the original threads.
8-40 Scope Screw Upgrade and Stripped Scope mount Screw Repair.
6-48 screw repair, for stripped scope mount screw. 8X40 screw upgrade, M4 scope screw repair. 8-40 scope mount screw conversion, ideal for when you have stripped scope screws. Especially useful for Bergara stripped or broken scope mount screws.
