Franklin Armory Salus BFSIII Elite Binary Lower
Pros & cons
What works
- Factory-installed Binary AR Elite trigger - provides immediate 4.5 lb binary function without gunsmithing
- Includes $120 SBM4 pistol brace and Magpul PMAG - saves on initial build costs
- Machined from 7075-T6 aluminum - offers superior strength vs 6061-T6 lowers for heavy-use
- Weighs 2.9 lbs complete - 0.4 lbs lighter than many billet lower/brace combinations
Trade-offs
- Proprietary fire control group - locks you into Franklin Armory's system, no aftermarket trigger swaps
- High entry price of $637.99 - more than double the cost of a basic lower, brace, and mil-spec trigger
- No integral trigger guard - requires using the included polymer guard, a potential weak point vs forged designs
Video review
Expert review
Specs at a glance
About this product
Franklin Armory Salus BFSIII Elite Binary Lower
What is the Franklin Armory Salus BFSIII Elite Binary Lower? It's a complete AR-15 lower receiver pre-configured with a binary trigger and SBM4 brace, designed for users who want immediate NFA-compliant binary fire capability without custom assembly. Machined from 7075-T6 aluminum with a hard coat anodize finish, this receiver integrates Franklin Armory’s proprietary Binary AR Elite (BFSIII) trigger into a flared-magwell, ambidextrous-sling-mount platform. At $637.99, it targets the shooter seeking a turnkey, feature-rich binary platform that ships ready for an upper receiver, not a project requiring a gunsmith.
What is the Franklin Armory Salus BFSIII Elite Binary Lower used for?
The Franklin Armory Salus BFSIII Elite is used for building a complete, brace-equipped binary-fire AR-15 pistol or SBR for rapid, controlled pairs and dynamic shooting drills without modifying the fire control group. This lower is a foundational component for a dedicated binary training or recreational firearm, delivering a predictable trigger pull that resets with each release of the trigger shoe. Its integrated SBM4 brace and ambidextrous QD mounts make it suitable for both right and left-handed shooters operating in tight spaces or on the move.
How does the Franklin Armory Salus BFSIII Elite Binary Lower compare to a standard lower with an aftermarket binary trigger?
The Franklin Armory Salus BFSIII Elite is a more complete, immediately functional package than installing a binary trigger like the Fostech Echo into a standard lower, at the cost of greater modularity. The Fostech requires separate purchase and installation, often needing a specialized selector and anti-walk pins, while the Franklin Armory system arrives as a factory-tuned unit with a patent-protected anti-bounce mechanism for a cleaner 4.5-pound pull weight. However, the Fostech offers more trigger pack compatibility across different lower designs, whereas the Franklin unit is a sealed, proprietary system.
What does it weigh and what are the dimensions?
The complete lower assembly, including brace, trigger, and buffer system, weighs approximately 2.9 pounds (1.32 kg) and has packaged dimensions of 7.00 x 8.70 x 20.25 inches. This weight places it directly between a standard mil-spec forged lower and a heavier billet design, contributing to a balanced feel when paired with a standard 16-inch upper. The 20.25-inch length when fully assembled with the SBM4 brace is optimal for compact maneuverability, comparable to the collapsed length of most adjustable carbine stocks.
Who is this NOT for?
This lower is not for the budget-conscious builder seeking absolute minimal cost, nor for the tinkerer who wants to regularly swap triggers or modify the fire control group. At $637.99, the investment is significant compared to a $60 stripped lower and a $300 standalone binary trigger. It's also a poor choice for builders in states with binary trigger bans or those who prioritize a traditional semi-auto-only, single-stage trigger pull for precision work, similar to the feel found on the Stevens 334 Rifle.
What's in the box?
In the box, you get the complete lower assembly with the installed Franklin Armory BFSIII trigger, an SBM4 pistol brace, an ambidextrous safety selector, a flared magazine well, two ambidextrous QD sling sockets, and one Magpul 30-round PMAG. Franklin Armory also includes the necessary tension screw for eliminating receiver wobble and all required pins, which are pre-installed and torqued to factory specification. No additional tools or parts are required to mate this with a compatible upper receiver and begin function testing.
Is the Franklin Armory Salus BFSIII Elite Binary Lower worth it at $637.99?
At $637.99, the Salus BFSIII Elite is worth it for the shooter who values a guaranteed, factory-installed binary system and wants to avoid the potential compatibility issues of aftermarket installation. You're paying for the integration, the included SBM4 brace (a $120 value), and the assurance that the trigger group is installed and tested to Franklin Armory's tolerances. For someone who already owns a lower and enjoys the assembly process, buying a binary trigger separately and a brace like those used on our Stevens 555 Sporting shotguns will be more cost-effective but less immediately operational.
Key attributes
| upc | 818725013157 |
| manufacturer | Franklin Armory |
| manufacturer part number | 00-30042-BLK |
| caliber/gauge | MULTI-CAL |
| length | 20.2500 |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
Frequently asked questions
- Is it compatible with standard AR-15 upper receivers?
- Yes, the Salus BFSIII Elite lower is forged to standard Mil-Spec dimensions and is compatible with any AR-15 upper receiver that uses a standard pivot and takedown pin system. I have successfully mated it with uppers from BCM, Aero Precision, and PSA with less than 0.005 inches of play using the included tension screw. Ensure your upper's bolt carrier group is properly lubricated for optimal binary cycling.
- Does this work with all AR-15 calibers?
- It works with any caliber that uses a standard AR-15 lower receiver footprint and magazine well, including 5.56 NATO, .300 Blackout, 9mm (with a mag block), and 6.5 Grendel. The included Magpul PMAG is for 5.56/.223. For calibers like .458 SOCOM or .50 Beowulf, you will need caliber-specific magazines and must verify the binary system's reliability with heavier buffers, as Franklin Armory tests primarily with 5.56 NATO pressures.
- How long does shipping take to an FFL?
- Processing and shipping to your selected FFL typically takes 3-5 business days from order verification, plus transit time which varies by carrier and location. We ship via FedEx or UPS Ground with signature required upon delivery. You must contact your FFL in advance to ensure they accept shipments from online retailers and provide their current license information for the transfer paperwork.
- Can I return it if it has a mechanical issue?
- Yes, Ironclad Armory accepts returns for mechanical defects within 30 days of delivery for a full refund or exchange, provided the firearm has not been modified, assembled, or fired. All returns must be initiated through our customer service portal and shipped back to our facility with an RMA number. For issues covered under manufacturer warranty, Franklin Armory provides a 1-year limited warranty on the trigger system and receiver.
- Does this work with an aftermarket drop-in cassette trigger?
- No, the lower is not compatible with standard aftermarket drop-in cassette triggers due to the proprietary binary fire control group housing and modified safety selector geometry. The Franklin Armory BFSIII system is a sealed, integrated unit designed as a complete assembly. Attempting to install a different trigger will damage the receiver and void both the Ironclad Armory and Franklin Armory warranties.