Tier-One Picatinny, RPA Quadlock

• RPA Quadlock fit: This Tier-One Picatinny rail is made specifically for the RPA Quadlock action, giving a secure interface for optics and helping maintain consistent alignment between rifle and sight.
• 7075-T6 aluminium construction: The rail uses a high-strength aluminium alloy that keeps weight down while providing the rigidity needed for stable scope mounting under regular field and range use.
• 5-axis CNC machining: Tier-One machines the rail from bar stock in one operation, which reduces cumulative setup error and supports precise slot geometry for dependable fit with Picatinny-compatible mounts.
• STANAG 4694 compliant design standard: By exceeding the manufacturing criteria for the metric Picatinny update, the rail is built for reliable compatibility with modern Picatinny mounting systems.
• Black low-profile finish: The black finish gives the rail a clean, unobtrusive appearance on the rifle and suits both sporting and tactical optics setups without adding visual bulk.

About the Tier-One Picatinny Rails Series

Tier-One Picatinny Rails are the company’s dedicated line of firearm-specific scope bases for shooters who want a precise, repeatable platform for mounting optics. The series is built around 7075-T6 aluminium construction and a manufacturing process in which each rail is machined from round bar stock to its finished form in a single operation on five-axis CNC machinery. In practical terms, that approach is intended to keep tolerances tight and preserve alignment across the full rail.

The range covers a broad selection of action types, from popular sporting rifles to specialist precision platforms, and includes variants in 0-, 10- or 20-MOA depending on the firearm pattern. Tier-One states that these rails exceed the manufacturing criteria for the STANAG 4694 NATO metric upgrade to the Picatinny standard, which is relevant for shooters who need dependable cross-compatibility with modern rings and mounts. Across the series, the design philosophy is straightforward: low unnecessary bulk, strong material choice, and action-specific geometry that gives hunting optics and precision shooting setups a stable base from the start.

About the Tier-One Picatinny, RPA Quadlock

The Tier-One Picatinny, RPA Quadlock is a dedicated scope base designed to fit the RPA Quadlock action and provide a stable Picatinny interface for riflescopes and other compatible sighting systems. Because it is made for this specific action pattern rather than as a universal rail, it is intended to sit correctly on the receiver and give the shooter a dependable foundation for ring placement, eye relief setup and overall optic alignment.

The rail is made from aluminium, which helps keep overall rifle weight under control while still delivering the stiffness expected from a quality optics base. For practical use, that matters when building a rifle that needs to remain balanced and manageable without sacrificing mounting security. Its black finish keeps the appearance discreet and matches a wide range of rifles, mounts and optics.

As part of Tier-One’s Picatinny rail family, this model benefits from the same emphasis on precise machining and standard-compliant slot geometry. That is important for shooters using Picatinny-compatible rings, as a well-made rail helps with repeatable installation and consistent engagement across the mounting surface. Whether the rifle is being set up for target work, varmint shooting or a general precision role, the Tier-One RPA Quadlock rail serves as the critical link between the action and the optic, supporting a clean, solid and properly matched mounting solution.

About Tier-One

Tier-One is a British shooting accessories manufacturer that was incorporated in early 2008. The company is based in the United Kingdom and focuses on precision-made rifle equipment, including scope mounts, bipods, moderators and related accessories. A defining part of Tier-One’s approach is that it manufactures products in-house on its own five-axis CNC machines, giving the brand close control over machining quality and consistency.

The company is well known for products such as the Monomount one-piece riflescope mounting system, and it has also produced OEM components for names including Blaser, Sauer, AI and March. Tier-One additionally manufactures precision scope rings for Zeiss USA. In this product category, that background matters because it shows long-standing expertise in the design and machining of mounting systems where fit, alignment and repeatability are central to performance.

Main Features

• Product type: Picatinny Rail
• Series: Tier-One Picatinny Rails
• Compatibility above: Picatinny Rail
• Compatibility below: RPA Quadlock
• Material: Aluminium
• Color: Black
• Made in: United Kingdom

Warranty

This Tier-One Picatinny rail is covered by a 10-year warranty, providing long-term support for a component that forms the mounting foundation of the rifle and optic setup.