Leupold BackCountry Cross-Slot, Nosler M21 SA

• 7075-T6 aluminum construction: The BackCountry Cross-Slot base uses a stronger aluminum alloy than basic mount bases, helping keep weight down without giving up the rigidity needed for a stable optic-to-rifle connection.
• Cross-slot interface: It accepts both Picatinny- and Weaver-style rings, giving broader ring compatibility and making it easier to match the base to an existing riflescope setup.
• One-piece design: A single-piece base creates a continuous mounting platform, which simplifies ring placement and helps maintain consistent alignment on a Nosler M21 Short Action.
• 0 MOA configuration: With no built-in cant, this base suits general hunting and field rifles where a neutral mounting angle keeps scope setup straightforward at typical zero distances.
• Made in the USA: Domestic manufacturing and Leupold’s long experience with hunting and shooting optics support consistent fit, finish, and dependable use in the field.

About the Leupold BackCountry Bases Series

Leupold BackCountry Bases sit within the company’s lightweight mounting range for hunters and shooters who want a practical balance of low mass, solid fit, and broad ring compatibility. As part of the wider BackCountry mount series, these bases are built for rifle-specific applications rather than a one-pattern-fits-all approach, which helps preserve proper fit on individual actions and keeps scope mounting straightforward.

A defining feature of the series is its use of 7075-T6 aluminum, a material choice that keeps the mount light while still providing the stiffness needed for repeatable optic support. The cross-slot format is designed to accept both Picatinny- and Weaver-style rings, which makes the series flexible for different riflescope and ring combinations. Leupold offers these bases in model-specific versions for actions such as the Remington 700, Winchester 70, and Nosler M21, with both 0 MOA and 20 MOA variants available depending on whether the rifle is intended for conventional zeroing or more elevation-biased long-range work.

About the Leupold BackCountry Cross-Slot, Nosler M21 SA

The Leupold BackCountry Cross-Slot, Nosler M21 SA is a one-piece base made specifically for the Nosler M21 Short Action. That model-specific fit matters because a base is not just an accessory; it is the foundation of the entire optic system. A properly matched base helps the rings sit correctly on the receiver, supports reliable scope alignment, and reduces the chance of unnecessary stress being introduced into the riflescope tube during installation.

This version uses a cross-slot pattern that accepts both Picatinny- and Weaver-style rings, which makes it easier to build around existing rings or choose from a wider range of scope mounting options. For a hunting rifle or general-purpose field setup, that flexibility is useful when balancing ring height, scope size, and eye position. The 0 MOA layout keeps the mounting plane neutral, which suits rifles that will be zeroed for normal hunting distances rather than dedicated long-range dialing.

Its 7075-T6 aluminum construction keeps weight low without making the base feel insubstantial, an important point on a rifle intended to be carried over distance. The matte finish gives it a subdued appearance that matches modern hunting optics and rifles, while the one-piece 160.00 mm platform provides generous ring placement latitude. In practice, this base is aimed at shooters who want a light, clean, and dependable mounting solution for a Nosler M21 SA rifle.

About Leupold

Leupold & Volpel was founded in Portland, Oregon, in 1907 by Fred Leupold and Adam Volpel. The company remains family-owned and focuses on sport optics for hunting, shooting, and outdoor use. Its product range includes riflescopes, red dot sights, binoculars, spotting scopes, rangefinders, and thermal optics, giving the brand a broad presence across both hunting and tactical shooting categories.

Leupold entered the riflescope market with the Plainsman in 1947 and later introduced the Duplex reticle in 1962, two milestones that helped establish its reputation in practical field optics. The company moved its manufacturing plant and headquarters to Beaverton, Oregon, in 1968, where Leupold & Stevens, Inc. is still headquartered today. That long focus on American-made optics and mounting systems is directly relevant to products like the BackCountry series, where fit, durability, and dependable field use matter as much as low weight.

Main Features

• Manufacturer: Leupold
• Series: Leupold BackCountry Bases
• Made in: USA
• Material: Aluminium
• Color: Matte
• Length: 160.00 mm
• Inclination: 0 MOA
• Compatibility above: Picatinny Rail
• Compatibility below: Nosler M21 SA

Warranty

Leupold provides a 10-year warranty for this mount base. That stated term adds clear long-term support for a component that plays a critical role in keeping a riflescope securely mounted and properly aligned.