What is the SA-15 Builders Kit?
A complete rifle build kit featuring Shield Arms' patented Folding Lower Receiver - no adapter required. Build your own custom folding AR-15 with 7075-T6 billet aluminum upper and lower, 15" M-LOK handguard, and proprietary folding system that's lighter, stronger, and more compact than traditional folding adapters. Perfect for custom builds with your choice of barrel, BCG, and furniture.
- Patented FLR: Revolutionary folding mechanism built into the receiver - no bulky adapter needed
- Custom Cerakote: In-house finishing in Fallout, Montana Mud, or Pineland - each kit is unique
- FFL Required: Lower receiver ships to your local FFL dealer (7-10 day processing)
Revolutionary Folding AR-15 Build Platform
The Shield Arms SA-15 Builders Kit is the foundation for building your own custom folding AR-15 rifle or pistol. Built around the revolutionary patented Folding Lower Receiver (FLR), this kit eliminates the need for bulky, heavy folding adapters while providing superior strength and compact folded dimensions.
Unlike traditional folding AR-15 builds that require aftermarket adapters, the SA-15 integrates the folding mechanism directly into the receiver design. This innovative approach results in a cleaner profile, reduced weight, shorter folded length, and enhanced reliability - all while maintaining full AR-15 compatibility and modularity.
Perfect for: Custom rifle builders, gunsmiths, enthusiasts seeking maximum compact storage, vehicle/truck guns, backpack rifles, and anyone who wants the advantages of a folding AR-15 without compromise.
What Makes the SA-15 Different?
Patented Folding Lower Receiver
- No adapter required - folding mechanism integrated into receiver design
- Lighter than adapter systems - eliminates heavy external hardware
- Shorter folded length - more compact than traditional folding adapters
- Stronger design - 7075-T6 billet aluminum construction throughout
- Carrier unmodified - works with any standard AR-15 bolt carrier group
- Robust folding mechanism - designed for thousands of folding cycles
- Quick deployment - unfolds and locks in seconds
Premium Billet Construction
- Upper Receiver: 7075-T6 billet aluminum - aerospace-grade strength
- Lower Receiver: 7075-T6 billet aluminum with integrated folding mechanism
- Precision machined - tighter tolerances than forged receivers
- Enhanced aesthetics - clean lines and modern appearance
- Full AR-15 compatibility - accepts standard AR-15 parts and accessories
Build-Ready Design
- Assembly-optimized - upper receiver and buffer tube threads left uncoated for proper torque values
- Included proprietary buffer - H2 weight buffer specifically designed for SA-15
- Blue Vibra-Tite provided - proper thread locker for assembly
- 15" M-LOK handguard - Shield Arms branded, lightweight, free-floating design
- Mil-Spec carbine buffer tube - accepts any standard AR-15 carbine stock or brace
Custom In-House Cerakote
- Four finish options: Black, Fallout, Montana Mud, Pineland
- Applied in-house - quality controlled by Shield Arms
- Unique patterns - no two kits are exactly alike
- Superior protection - exceptional corrosion and wear resistance
- Assembly-friendly - critical surfaces left uncoated for proper torque
Technical Specifications
| Kit Name |
SA-15 Builders Kit |
| Upper Receiver |
Stripped 7075-T6 Billet Aluminum |
| Lower Receiver |
Shield Arms SA-15 Stripped Folding Lower Receiver |
| Lower Receiver Material |
7075-T6 Billet Aluminum |
| Folding Mechanism |
Patented integrated design (no adapter) |
| Handguard |
Shield Arms 15" M-LOK (free-floating) |
| Buffer Tube |
Carbine Mil-Spec |
| Buffer |
Shield Arms Proprietary H2 Weight |
| Thread Locker |
Blue Vibra-Tite (included) |
| Cerakote Finish Options |
Black, Fallout, Montana Mud, Pineland |
| Cerakote Application |
In-house (each kit unique) |
| Assembly Note |
Upper receiver threads and buffer tube threads left uncoated |
| BCG Compatibility |
Any standard AR-15 bolt carrier group (unmodified) |
| Upper Receiver Type |
Flat-top with Picatinny rail |
| Lower Receiver Type |
Multi-caliber compatible |
| FFL Required |
Yes (lower receiver) |
| Warranty |
100% Lifetime |
| Made In |
USA (Montana) |
Custom Cerakote Finish Options
All Cerakote finishing is done in-house at Shield Arms. Each builders kit is truly custom - no two are exactly alike!
Available Finish Options
Black - Classic matte black Cerakote finish. Professional appearance with excellent durability and corrosion resistance. The most versatile choice for any build style - tactical, hunting, or competition.
Fallout - Custom distressed pattern inspired by post-apocalyptic aesthetics. Unique worn appearance with character and depth. Perfect for tactical/battle-worn look enthusiasts and custom builds with personality.
Montana Mud - Earth-tone camouflage pattern featuring browns, tans, and grays. Excellent for hunters and outdoor use. Blends naturally with wilderness environments while maintaining a rugged, field-ready appearance.
Pineland - Military-inspired green and brown camouflage pattern. Named after the fictional location used in Special Forces training. Tactical aesthetic with outdoor versatility for serious builds.
Important Notes:
- All patterns are hand-applied - expect natural variation between kits
- Custom finishes add unique character to each build
- Upper receiver threads and buffer tube threads intentionally left uncoated for proper assembly torque
- Select your preferred finish during checkout
- Cerakote provides superior corrosion and wear resistance over anodizing
- All finishes available at the same base price
Why Choose SA-15 Over Traditional Folding Adapters?
| Feature |
SA-15 Builders Kit |
Traditional Folding Adapter |
| Folding Mechanism |
Integrated into receiver (patented) |
External adapter required |
| Weight |
Lighter (no additional hardware) |
Heavier (adapter adds .5 lbs or more) |
| Folded Length |
More compact |
Longer due to adapter bulk |
| Bolt Carrier |
Unmodified - any standard BCG works |
Often requires modified carrier |
| Aesthetics |
Clean, integrated design |
Bulky adapter visible |
| Strength |
Billet construction throughout |
Adapter creates potential weak point |
| Cost |
Integrated (no adapter to buy) |
Adapter costs $200-400 separately |
| Assembly |
Standard AR-15 build process |
Requires adapter installation and timing |
What's Included in the Kit
Core Components
- SA-15 Stripped Folding Lower Receiver - 7075-T6 billet with integrated folding mechanism
- Stripped Upper Receiver - 7075-T6 billet with flat-top Picatinny rail
- 15" M-LOK Handguard - Shield Arms branded, free-floating design
- Carbine Buffer Tube - Mil-Spec compatible with any carbine stock or brace
- Proprietary H2 Buffer - Shield Arms buffer designed specifically for SA-15
- Blue Vibra-Tite - Thread locker for proper assembly
What You'll Need to Complete Your Build
The SA-15 Builders Kit provides the foundation. You'll need these components to complete your rifle or pistol:
Essential Components
- Barrel - any AR-15 barrel (5.56 NATO, .223 Wylde, .300 BLK, etc.)
- Bolt Carrier Group (BCG) - any standard AR-15 BCG (no modification needed)
- Charging Handle - any AR-15 charging handle
- Lower Parts Kit (LPK) - trigger, hammer, pins, springs, etc.
- Stock or Brace - any carbine-length stock (rifle) or pistol brace (pistol)
- Pistol Grip - any AR-15 pistol grip
- Muzzle Device - flash hider, muzzle brake, or compensator
- Gas System - gas block and gas tube (length matches barrel)
Recommended Accessories
- Optic - red dot, holographic, or scope (upper has Picatinny rail)
- Backup Sights - folding or fixed iron sights
- Sling - two-point or single-point sling system
- M-LOK Accessories - vertical grip, hand stop, lights, laser
- Enhanced Trigger - Geissele, CMC, Trigger Tech, etc.
Assembly Considerations & Tips
Important Assembly Notes
- Uncoated threads: Upper receiver and buffer tube threads are intentionally left uncoated to ensure proper torque values and tight fit
- Use Blue Vibra-Tite: Apply included thread locker to appropriate fasteners during assembly
- Standard tools required: AR-15 armorer's wrench, torque wrench, punches, vise, vise blocks
- Follow barrel nut torque specs: Typically 30-80 ft-lbs depending on barrel nut design
- Test folding function: Before final assembly, verify folding mechanism operates smoothly
Build Configurations
The SA-15 Builders Kit supports multiple build configurations:
Rifle Configuration (16"+ barrel with stock)
- No NFA registration required
- Use carbine-length stock on included buffer tube
- Choose barrel length 16" or longer
- Ideal for: hunting, long-range, general purpose
Pistol Configuration (barrel under 16" with brace)
- No NFA registration required (if using brace, not stock)
- Use pistol stabilizing brace on included buffer tube
- Popular barrel lengths: 7.5", 10.5", 11.5", 12.5"
- Ideal for: compact storage, vehicle guns, backpack carry
- Verify current ATF brace regulations
SBR Configuration (barrel under 16" with stock)
- Requires ATF Form 1 and $200 tax stamp
- NFA registration mandatory before assembly
- Use carbine stock after approval
- Shortest, most versatile configuration
Caliber Options
The SA-15 lower receiver is multi-caliber compatible. Popular caliber choices:
- 5.56 NATO / .223 Wylde - Most common, affordable ammunition
- .300 Blackout - Excellent suppressed, subsonic capable
- .350 Legend - Straight-wall cartridge for restricted hunting areas
- 6.5 Grendel - Long-range precision option
- .224 Valkyrie - Extended-range performance
Use Cases & Applications
Perfect For:
Custom Rifle Builders - Start with premium folding platform and build exactly what you want. Choose your own barrel, trigger, optic, and furniture for a truly personalized rifle.
Truck / Vehicle Guns - Folding capability provides ultra-compact storage in vehicles. Build a short-barreled pistol configuration for maximum compactness when folded.
Backpack / Get Home Rifles - Compact folded dimensions fit in backpacks and emergency bags. Build lightweight configuration for extended carry without fatigue.
Hunting Rifles - Folding design excellent for ATV/UTV transport and compact storage while hunting. Build in .300 Blackout or .350 Legend for suppressed or straight-wall hunting.
Competition Builds - Lightweight billet construction ideal for 3-Gun or other competition formats. Build with match barrel and enhanced trigger for precision performance.
Home Defense - Compact storage when folded, quick deployment when needed. Build in 5.56 NATO or .300 Blackout with suppressor-ready barrel.
Suppressor Hosts - Build with threaded barrel for suppressed shooting. Folding design maintains compact dimensions even with suppressor attached.
FFL Transfer & Shipping Information
The SA-15 Builders Kit includes a lower receiver, which is a firearm and requires transfer through a Federal Firearms Licensed (FFL) dealer.
Shipping Timeline
Important: Due to custom Cerakote finishing and FFL processing requirements, shipping may take 7-10 business days after your order is placed and FFL documentation is received.
How FFL Transfer Works
- Place Your Order: Purchase the SA-15 Builders Kit and select your preferred Cerakote finish
- Select Your FFL: Choose your preferred local FFL dealer during checkout
- FFL Documentation: Your chosen FFL will send their license to Shield Arms
- Processing & Shipping: Shield Arms applies custom Cerakote and ships to your FFL (7-10 days)
- Pickup: Visit your FFL to complete ATF Form 4473 background check and take possession
Important Requirements
- Must be 18+ years old to purchase lower receiver (21+ for pistol configuration)
- Must comply with all federal, state, and local firearms laws
- Your FFL may charge a transfer fee (typically $25-50)
- Cannot be shipped to prohibited states/localities - check your local laws
- If building pistol with brace: Verify current ATF regulations
- If building SBR: Must complete ATF Form 1 before assembly
Need help finding an FFL? Shield Arms can assist you in locating an FFL dealer near you. Contact customer service after placing your order.
Frequently Asked Questions
What's the difference between this and buying a complete folding lower?
The SA-15 Builders Kit includes both the stripped folding lower receiver AND the matching stripped upper receiver, plus handguard, buffer tube, proprietary buffer, and thread locker. It provides everything except the components you'd want to choose yourself (barrel, BCG, trigger, furniture). A complete folding lower would include the lower parts kit and stock/brace but not the upper components.
Do I need a modified bolt carrier group?
No! Unlike most folding adapter systems, the SA-15 works with any standard, unmodified AR-15 bolt carrier group. The folding mechanism is built into the receiver, not the carrier. This saves you money and gives you more BCG options.
Why are some surfaces left uncoated?
The upper receiver threads and buffer tube threads are intentionally left uncoated to ensure proper assembly. Cerakote, while durable, adds thickness that can interfere with achieving correct barrel nut torque values and tight fits. This is a deliberate design choice to help you build correctly.
Can I build this as a pistol or does it have to be a rifle?
You can build either configuration. For a pistol: use a barrel under 16" and install a pistol stabilizing brace (verify ATF regulations). For a rifle: use a 16"+ barrel and install a carbine stock. If you want a short-barreled rifle (SBR) with stock and barrel under 16", you must complete ATF Form 1 and pay the tax stamp BEFORE assembly.
What calibers can I build with this kit?
The SA-15 lower receiver is multi-caliber compatible. Most popular choices are 5.56 NATO and .300 Blackout, but you can build in any caliber compatible with AR-15 bolt face and magazine well dimensions.
How compact does it fold?
The SA-15 folding mechanism provides exceptional compact dimensions when folded - significantly shorter than traditional folding adapters. Exact folded length depends on your build configuration, but typically 13-15" for pistol builds and 16-18" for rifle builds. This is 3-5" shorter than most folding adapter systems.
Do you offer builder support or assembly guides?
Yes! Shield Arms provides detailed assembly instructions and builder support. The SA-15 assembles like a standard AR-15 with a few specific considerations for the folding mechanism. If you can build a standard AR-15, you can build an SA-15. Contact customer service if you have assembly questions.
Is the handguard free-floating?
Yes. The included 15" M-LOK handguard is free-floating, which improves accuracy by not contacting the barrel. It attaches to the upper receiver with a barrel nut system and provides M-LOK attachment points for accessories.
Can I use this with a suppressor?
Absolutely. Build with a threaded barrel (most AR-15 barrels have 1/2x28 threads for 5.56 or 5/8x24 for .308) and you're suppressor-ready. The folding mechanism works perfectly with suppressors attached. Many builders choose the SA-15 specifically for suppressed builds because of the compact folded dimensions.
How difficult is this to assemble?
If you have basic AR-15 building experience and the proper tools (armorer's wrench, torque wrench, punches, vise), this is a straightforward build. The SA-15 uses standard AR-15 assembly procedures. If this is your first build, consider having a gunsmith assist or watching detailed AR-15 build videos before starting.
What's included with the proprietary buffer?
The kit includes Shield Arms' proprietary H2-weight buffer specifically designed for the SA-15 folding system. This buffer ensures reliable cycling and proper bolt lockup. You'll also receive Blue Vibra-Tite thread locker for assembly.
What is the warranty on the SA-15 Builders Kit?
Shield Arms backs the SA-15 Builders Kit with a 100% Lifetime Warranty against manufacturing defects in the receivers, handguard, buffer tube, and buffer. If you experience any issues with materials or workmanship, Shield Arms will repair or replace free of charge.
Who Should Buy the SA-15 Builders Kit?
- Custom Rifle Builders - Want to build their own folding AR-15 with specific components
- AR-15 Enthusiasts - Appreciate innovative design and billet quality over forged receivers
- Hunters - Need compact storage for ATV/UTV transport and field use
- Vehicle Gun Owners - Require ultra-compact folding rifle for truck/car storage
- Preppers & Survivalists - Want folding get-home rifle they can customize exactly as needed
- Competition Shooters - Value lightweight billet construction for 3-Gun or other formats
- Suppressor Enthusiasts - Plan to build suppressor host with folding capability
- Gunsmiths - Building customer rifles with premium folding platform
- Collectors - Appreciate patent-pending technology and American innovation
- Minimalists - Want clean, integrated folding design without bulky adapters
Summary: Is the SA-15 Builders Kit Right for You?
The Shield Arms SA-15 Builders Kit is the ultimate foundation for building a custom folding AR-15. Unlike traditional builds that require expensive, bulky folding adapters, the SA-15 integrates the patent-pending folding mechanism directly into the receiver - resulting in lighter weight, shorter folded length, and cleaner aesthetics.
Key Advantages:
- Patented folding lower receiver - no adapter needed
- Lighter, stronger, more compact than adapter-based folding systems
- 7075-T6 billet construction for upper and lower receivers
- Works with unmodified standard AR-15 bolt carrier groups
- Includes 15" M-LOK handguard, buffer tube, proprietary buffer, thread locker
- Custom in-house Cerakote in four finish options - each kit unique
- Assembly-optimized design with strategic uncoated surfaces
- Multi-caliber compatible - build in 5.56, .300 BLK, .350 Legend, more
- Configure as rifle, pistol, or SBR (with proper paperwork)
- Made in USA with lifetime warranty
Perfect for: Custom builders who want premium folding AR-15 platform without the compromises of traditional folding adapters. Ideal for vehicle guns, backpack rifles, hunting builds, suppressed firearms, and anyone who values compact storage combined with full AR-15 modularity.
Why SA-15 Over Folding Adapters: Integrated folding saves weight, reduces folded length, eliminates adapter cost, maintains cleaner appearance, and works with unmodified carriers. The SA-15 is the only AR-15 platform with these integrated folding advantages.
Ready to start your build? Select your preferred Cerakote finish and add the SA-15 Builders Kit to your cart. Please note that due to custom finishing and FFL processing, shipping takes 7-10 business days. Your local FFL dealer will contact you when ready for pickup, then you can begin building your dream folding AR-15.
Questions before ordering? Contact Shield Arms customer service for expert guidance on the SA-15 Builders Kit, build recommendations, FFL transfer process, or any other questions about this revolutionary folding AR-15 platform.
