Osuma Pair of Rings for Optilock Base, 40 mm

• Optilock-base compatibility: Built to fit original Optilock mounting bases, these rings provide a straightforward way to keep a proven base system while adapting it to a 40 mm scope tube.
• 40 mm ring diameter: The larger ring size supports specialized optics with a 40 mm main tube, giving secure, correctly matched clamping without improvised inserts or adapters.
• Aluminium construction: The aluminium body keeps weight down while still providing the rigidity needed for a stable scope-to-rifle connection in hunting and range use.
• Anodized black finish: The black anodized surface helps resist wear and handling marks, while also matching modern rifles and optics with a low-visibility appearance.
• Ø 7 mm interface support: Compatibility with EAW, Optilock, Osuma and Recknagel Ø 7 mm interfaces makes these rings useful for shooters working across several established mounting standards.

About the Osuma Optilock Base Rings Series

Osuma Optilock Base Rings are designed as a dedicated ring solution for rifles already using original Optilock mounting bases. Within Osuma’s mounting lineup, this series serves shooters who want a clean, purpose-built way to mount different scope tube diameters without changing the underlying base system. That makes the series especially relevant for hunting rifles and precision setups where the base is already in place and trusted.

The series is built around high-grade aluminium construction with an anodized surface, combining low weight with the durability expected from a field-use scope mounting component. Osuma offers the rings in several tube diameters, including 30 mm, 34 mm, 36 mm and 40 mm, with different height options across the range so the shooter can match the optic to the rifle and barrel profile more precisely. The 40 mm version is listed in low height, making it suitable for setups where keeping the optic close to the bore is a priority. Sold in pairs, the series focuses on practical compatibility, straightforward installation and a secure mechanical fit rather than unnecessary complexity.

About the Osuma Pair of Rings for Optilock Base, 40 mm

The Osuma Pair of Rings for Optilock Base, 40 mm is a specialized scope-mounting solution for rifles fitted with Optilock-style bases and optics that use a 40 mm main tube. That makes it particularly relevant for shooters using larger-tube target or long-range optics that need a ring set matched to both the scope body and the existing base interface. Instead of replacing the whole mounting system, this model lets the rifle retain its established base arrangement while accommodating a less common tube diameter.

This ring pair is made from aluminium, which helps keep overall rifle weight under control while still providing the stiffness needed for consistent scope alignment. In practice, that matters on hunting rifles carried over long distances as well as on range rifles where a stable optic position is essential for repeatable zero. The black finish gives the rings a discreet appearance and suits modern riflescope setups without drawing attention to the mounting hardware.

Compatibility is a key strength of this model. In addition to fitting Optilock Ø 7 mm interfaces, it is also listed as compatible with EAW Ø 7 mm, Osuma Ø 7 mm and Recknagel Ø 7 mm interfaces. That broader fitment can simplify parts selection for shooters working with rifles or bases built around the same Ø 7 mm standard. With KR 0.0 mm extension, the design stays neutral and compact, making it a practical choice when the optic can be positioned correctly without offset.

About Osuma

Osuma is a Finland-based brand focused primarily on rifle scope mounting. Its history goes back to the early 1990s, when the company’s owner developed the first mounts for his own hunting and benchrest shooting needs. That origin is still reflected in the product range, which centers on practical mounting solutions shaped by real rifle use rather than generic hardware design.

Osuma designs and manufactures its products in Finland, and its catalog includes more than 150 products. The range covers scope mounts, scope rings, rail mounts, red-dot and holosight mounts, suppressors and accessories such as the Trigger Widener. The company has passed from father to son, and its reputation is closely tied to durable aluminium mounting components with an anodized finish and broad compatibility across systems such as 11 mm, Tikka 17 mm, Sako, Picatinny, Optilock and Blaser.

Main Features

• Manufacturer: Osuma
• Series: Osuma Optilock Base Rings
• Made in: Finland
• Warranty: 2 years
• Material: Aluminium
• Extension (KR): KR 0.0 mm
• Scope / sight type: 40 mm
• Color: Black
• Compatibility above: 40 mm
• Compatibility below: EAW Ø 7 mm Interface
• Compatibility below: Optilock Ø 7 mm Interface
• Compatibility below: Osuma Ø 7 mm Interface
• Compatibility below: Recknagel Ø 7 mm Interface

Warranty

Osuma states a 2-year warranty for this product. That period suits a precision-machined mounting component intended for regular field and range use.