Fierce Firearms Chassis Kit — Tungsten Gray | Fits AR-15 Short Action* | Model SACHSTU | UPC 853418803905
Transform your rifle into a precision-tuned platform with the Fierce Firearms Chassis Kit in Tungsten Gray. Engineered for stability, ergonomics, and modularity, the SACHSTU chassis delivers a rock-solid bedding surface, modern M-LOK® mounting options, and an adjustable, shooter-centric stock system—so you can tailor balance, length of pull, and cheek height to your optic and shooting style. From varmint fields to steel at distance, this chassis gives your build the rigidity and repeatability needed to turn consistency into confidence.
Model/SKU: SACHSTU
UPC: 853418803905
Finish/Color: Tungsten Gray
Fitment: AR-15 short-action pattern* (see compatibility notes below)
*“Short action” is often used generically to describe rifle receiver lengths. AR-15 platforms typically house intermediate/short cartridges (e.g., .223/5.56, 224 Valkyrie, 6mm ARC, 6.5 Grendel). Always verify action/receiver interface prior to purchase.
Why Upgrade to the Fierce Chassis (Tungsten Gray)
Precision foundation: A rigid monolithic chassis resists flex, offering a consistent interface that helps preserve zero and shrink groups through heat cycles and round counts.
Shooter-first ergonomics: Adjustable length of pull and cheek height dial your eye-to-optic alignment and support a relaxed, repeatable head position.
Modular M-LOK® architecture: Mount bipods, ARCA adapters, barricade stops, QD sling cups, and tripods exactly where you need them—without extra bulk.
Tungsten Gray finish: A durable, low-glare coating that looks professional and shrugs off field wear, range grime, and weather.
Balance & control: Thoughtful geometry improves rear bag tracking and barricade control for steadier sight pictures and smoother recoil return.
Drop-in modernization: Bring legacy uppers/lowers into a modern precision workflow with improved ergonomics and accessory placement.
Key Features at a Glance
Chassis Type: Precision rifle chassis for AR-15 short-action interfaces*
Adjustability: Cheek riser & length of pull micro-adjustment (tool or tool-less depending on hardware—verify package)
Forend: M-LOK® slots at multiple clock positions for accessories and weights
Buttstock Area: Flat geometry for consistent rear-bag rides; integrated QD points (verify included cups)
Pistol Grip Interface: AR-style grip compatibility (choose an angle/texture you prefer)
Slinging: QD provisions and traditional sling options (hardware may vary by lot)
Finish: Tungsten Gray, abrasion-resistant
SKU: SACHSTU | UPC: 853418803905
What’s included can vary. Some kits ship with mounting hardware, spacers, and QD cups; others do not. Confirm in-the-box contents, buffer system requirements, and specific receiver interface with your retailer.
Real-World Performance Benefits
Repeatable accuracy: A stiff chassis eliminates stock swell and bedding shifts common to traditional furniture—your cold-bore and follow-up shots stay predictable.
Natural eye alignment: Fine cheek/LOP adjustments reduce neck strain and parallax error for faster target acquisition and steadier holds.
Stable support options: Flat, weight-friendly forend and buttstock geometry track straight on bags and barricades—ideal for PRS-style stages and field positions.
Weather-proof duty: Metal chassis construction tolerates rain, dust, and temperature swings; cleanup is fast and simple.
Ideal Use Cases
Predator & varmint hunting: Add a light, quick-deploy bipod and run stable, low-recoil strings on small targets.
Steel & competition practice: M-LOK® rails and tunable balance let you build a fast, forgiving positional rifle.
General precision carbine: Pair with a quality barrel and optic to create a dependable do-everything rig.
Compatibility & Fit Notes
Designed around AR-15-size receivers. Confirm your upper/lower pattern, magazine spec, and buffer/receiver extension compatibility before installation.
Works with a wide range of AR-style pistol grips and M-LOK® accessories.
Barrel contour/handguard clearance: verify your gas block size and muzzle device length for proper fit with the forend and any full-length rails.
If using ARCA or heavy weights, select the appropriate adapters/rails for your M-LOK® slots.
Suggested Setup (Pro Tips)
Optic: A 3–15x or 4–16x with zero stop and consistent tracking; mount low for a solid cheek weld.
Support: Compact bipod (cant/lock), rear bag sized to the buttstock geometry, and a micro barricade stop up front.
Trigger: A crisp single-stage or two-stage trigger helps capitalize on the chassis’ stability.
Balance: Add M-LOK® weights or ARCA plate to tune center of gravity for positional stages or prone work.
Sling: Two-point QD sling for carry and quick loop-up shooting support.
Installation (Quick Guide)
Unload & clear your firearm.
Separate upper and lower; remove existing stock/handguard/furniture as required.
Fit receiver to the chassis per instructions; apply proper torque to action/receiver screws.
Adjust cheek riser and length of pull to your optic/position.
Verify function: Check safety, trigger, magazine insertion/ejection, and bolt travel.
Zero & confirm: Confirm torque after the first range session and re-zero if needed.
If you’re unsure about interface, torque specs, or bedding hardware, consult a qualified gunsmith or armorer.
Care & Maintenance
Wipe down with a damp cloth; avoid harsh solvents on finish and polymer components.
Re-torque action/rail screws on a seasonal schedule or after hard travel.
Inspect M-LOK® accessories and QD points for tightness prior to use.
Protect exposed metal and fasteners with a light corrosion inhibitor in humid/salty environments.
Specifications (Quick Reference)
Brand: Fierce Firearms
Product: Chassis Kit (Tungsten Gray)
Fitment: AR-15 short-action* pattern (verify specific receiver interface)
Adjustability: Cheek height & length of pull
Mounting: M-LOK® forend; QD sling provisions (varies)
Finish: Tungsten Gray, low-glare
SKU: SACHSTU
UPC: 853418803905
Frequently Asked Questions
Q: Will this chassis fit my large-frame AR-10 (.308) build?
A: It’s designed for AR-15-size receivers. Large-frame receivers often use different dimensions and may not be compatible.
Q: Is an ARCA rail included?
A: Typically sold M-LOK®-only; add ARCA plates/rails as needed. Check the listing for included accessories.
Q: Can I run a folding mechanism?
A: Folding adapters depend on your buffer/receiver extension setup. Verify compatibility with your chosen folder and recoil system.
Q: What torque should I use?
A: Follow the manufacturer’s torque values for action screws and M-LOK® hardware. When in doubt, consult a qualified armorer.
Q: Does the color match common Tungsten finishes?
A: Tungsten Gray is a popular neutral; exact shade can vary slightly by batch and lighting.
SEO-Friendly Highlights (Naturally Woven)
Fierce Firearms Chassis Kit Tungsten Gray, AR-15 short-action precision chassis, M-LOK® rifle chassis with adjustable cheek riser and length of pull, rigid bedding for repeatable accuracy, rear-bag friendly stock, modular precision rifle chassis SACHSTU, UPC 853418803905.
Meta for Your Product Page
Meta Title: Fierce Firearms Chassis Kit — Tungsten Gray | AR-15 Short-Action | SACHSTU
Meta Description: Upgrade to precision with the Fierce Tungsten Gray Chassis Kit for AR-15 short-action builds. Adjustable cheek/LOP, M-LOK® forend, rigid accuracy foundation. Model SACHSTU — UPC 853418803905.
Build it light, build it strong, and build it repeatable—the Fierce Firearms Chassis Kit (Tungsten Gray) gives your AR-15-size rifle the modern, modular backbone it deserves.
The End
