KMRNL ASR Magazine Brace V3 – Sig Sauer Cross Magnum Sawtooth .300 (3.850″) Baseplate Upgrade | Patent Pending

Upgrade your Sig Sauer Cross Magnum Sawtooth .300 (3.850″) ASR magazine with the KMRNL ASR Magazine Brace — a patent-pending, baseplate-replacement that enhances stability, modularity, and feeding reliability without altering the magazine’s internal geometry.

What’s new in V3

• Wider footprint – More contact area for bench/pack/barricade support while keeping Arca rail dimensions unchanged for full compatibility.
• Thicker body mass – Slightly increased weight to help settle the rifle and reduce perceived recoil movement.
• Longer brace cleats – Deeper bite on surfaces for improved grip and stability.
• Redesigned M-LOK area – Ergonomics align in-line with the rifle, with a purposeful cant so accessories (e.g., lights, lasers, two-round holders) mount naturally.

Both Versions Share:

• Seamless integration – Slides on in place of the factory baseplate; retains factory internals.
• Arca-compatible rail – Unchanged dimensions from prior versions for tripod/stabilizer use.
• Vertical magazine posture – Promotes a flush fit with the receiver for bracing without interference.
• Feeding reliability – Geometry that supports proper alignment during cycling.
• Removable back panel – Single fastener for quick insert/removal of the magazine (original design retained).
• Rugged glass-filled polymer housing – Built for harsh environments (proprietary, glass-filled polymer comparable to PA6-GF).

Choose Your Version

• V3 (Recommended) – Wider footprint, thicker mass for recoil control, longer cleats, refined M-LOK area (ergonomic & canted). Arca dimensions unchanged.
• Original – Proven performance with the same Arca rail and removable back panel design.

Tip: If you run off tripods, barricades, or shoot from bags, V3’s footprint and cleats provide a noticeable stability gain.

Compatibility

• Rifle: Sig Sauer Cross Magnum Sawtooth platform.
• Magazine: Accurate-Mag ASR magazine in .300 WM (3.850″) configuration (factory ASR mag used by the Cross Magnum Sawtooth).
• No permanent mods: Reversible to stock baseplate at any time.

Note: Designed around the Cross Magnum Sawtooth receiver and factory ASR magazine. If your setup differs, contact us before ordering.

Key Uses

• Precision/PRC: Stable, repeatable interface for bags, rails, and tripods.
• Field & hunting: Low-profile, flush support without snagging.
• Training: Consistent magazine alignment supports reliable feeding.

Installation

PDF Instructions: ASR instructions

1. Remove the factory baseplate from the ASR magazine.
2. Detach the back panel on the KMRNL ASR Magazine Brace.
3. Slide the brace onto the magazine body, fully seated.
4. Insert the magazine into the rifle to confirm alignment, then reattach the back panel for a tight, flush fit.

Specs & Materials

• Material: Proprietary glass-filled polymer (engineered for stiffness and impact resistance).
• Arca rail: Arca-Swiss compatible; same dimensions as prior revision.
• Mounting: M-LOK style slots with ergonomic, canted orientation for accessory clearance.
• Finish: Matte, utility-driven texture for grip.

Legal & IP Respect

KMRNL fully respects and acknowledges all patents, trademarks, and intellectual property associated with the Sig Sauer Cross rifle, the factory ASR magazine, and components by third parties such as Accurate-Mag. This product is a patent-pending, independently engineered accessory that replaces only the factory baseplate and preserves the magazine’s original body, spring, follower, and feed geometry.

What’s in the Box

• KMRNL ASR Magazine Brace (choose V3 or Original)
• Back panel & fastener
• Quick-start guide (link to full PDF above)

Customer Photos & Videos

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