Franklin Armory BFSIII M4-SBR-L XTD 5.56mm 16″Barrel Black

Description

The Franklin Armory BFSIII M4-SBR-L XTD in 5.56mm with a 16-inch barrel delivers a purpose-built AR platform for shooters who demand rapid, reliable binary fire without sacrificing accuracy or build quality. This franklin armory bfsiii m4-sbr-l xtd 5.56mm 16″barrel black rifle combines a mid-length gas system with a 15-inch FSR handguard, Magpul furniture, and a salt bath nitride bolt carrier for corrosion resistance and smooth cycling. It is a complete, ready-to-run rifle built around Franklin Armory’s proven Binary Firing System III trigger, offering a disciplined, two-position fire control that rewards deliberate trigger manipulation.

Specification	Detail
Manufacturer	Franklin Armory
Model	BFSIII M4-SBR-L XTD
Material	7075-T6 Aluminum upper and lower (per manufacturer specs)
Compatibility	5.56mm NATO / .223 Remington
Finish	Type III Hard Coat Anodized, Black
Weight	6 lbs 14 oz (unloaded, per Franklin Armory)
Condition	New

Key Features

• Binary Firing System III Trigger: Why it matters – This trigger allows one round on the pull and one on the release, giving you a controlled, rapid-fire capability without modifying the lower receiver or requiring a tax stamp. It is a drop-in, user-installable unit that maintains safe, semi-automatic functionality when used in standard mode.
• 16-Inch M4 SBN Barrel with Mid-Length Gas System: Why it matters – The mid-length gas system reduces felt recoil and carrier speed compared to carbine-length, improving reliability and parts longevity. The 1/7 twist stabilizes a wide range of bullet weights, from 55-grain to 77-grain loads.
• 15-Inch FSR Handguard with Bilateral Push Button QD Mounts: Why it matters – Free-float construction enhances accuracy by removing barrel pressure points, while the QD sling mounts on both sides allow ambidextrous sling attachment without additional hardware.
• Magpul CTR Stock and Ergo Ambi Sure Grip: Why it matters – The CTR stock offers a friction-lock system to reduce wobble, and the Ergo grip provides a positive, non-slip texture for rapid target reacquisition. Both components improve shooter comfort and control during extended range sessions.
• Salt Bath Nitride Bolt Carrier Group: Why it matters – This surface treatment penetrates the metal to reduce friction and resist fouling, extending the BCG service life between cleanings. It also simplifies maintenance because carbon buildup wipes off easier than on standard phosphate finishes.

Who It’s For

This rifle is built for the experienced shooter who wants a legal, binary-fire-capable AR without the hassle of a Form 1 or Form 4. It suits competitive shooters in outlaw matches, tactical trainers who want to simulate controlled pairs, and collectors who appreciate Franklin Armory’s engineering pedigree. It is not a beginner’s rifle – the binary trigger requires discipline and a solid understanding of firearm safety.

Pros and Cons

Pros:

• Drop-in binary trigger requires no gunsmithing
• Mid-length gas system plus 16-inch barrel balances recoil and velocity
• Free-float handguard with QD points is ready for optics and slings
• Salt bath nitride BCG resists corrosion and runs smoother longer

Cons:

• Binary mode can be disorienting for shooters new to the system; practice is required to avoid bump-fire confusion
• Price point is higher than many standard ARs – you pay for the trigger and the complete build

Comparison Table

Feature	Franklin Armory BFSIII M4-SBR-L XTD	Geissele Super Duty 16-inch	Zev Technologies AR-15 16-inch
Trigger	Binary Firing System III	Geissele SSA-E (two-stage)	Mil-spec (upgradable)
Barrel Twist	1/7	1/7	1/8
Gas System	Mid-length	Mid-length	Carbine-length
Handguard	15-inch FSR free-float	15-inch MK16 free-float	15-inch M-LOK free-float
Weight (unloaded)	6 lbs 14 oz	7 lbs 2 oz	6 lbs 10 oz
MSRP	$1,512.80	$1,899.00	$1,799.00

Frequently Asked Questions

Does the Franklin Armory BFSIII trigger require any modification to the lower receiver?

No. The BFSIII is a drop-in trigger cassette that fits standard mil-spec AR-15 lower receivers. You do not need to drill, file, or modify any part of the lower for installation. It uses the same hammer, trigger, and disconnector pins as a standard trigger group.

Can this rifle be used with a suppressor?

Yes, but the 16-inch barrel and mid-length gas system already reduce port pressure. If you add a suppressor, you may need to adjust the buffer weight or use an adjustable gas block to maintain reliable cycling. The handguard’s 1.3-inch internal diameter accommodates most standard suppressors without clearance issues.

Is the binary trigger legal in all states?

No. Binary triggers are prohibited in several states, including California, New York, New Jersey, and others. Check your local and state laws before purchasing. The rifle itself is a standard semi-automatic AR-15 when the trigger is used in semi-auto mode, but the binary function may be restricted in some jurisdictions.

What ammunition does the 1/7 twist barrel prefer?

The 1/7 twist rate stabilizes bullets from 55 grains up to 77 grains. It performs best with 62-grain to 69-grain match loads, but it will shoot 55-grain M193 ball accurately for general plinking. Avoid bullets under 50 grains, as they may not stabilize well.

Trust & Delivery

• ✓ Nationwide delivery to all 50 states
• ✓ Ships within 1-2 business days
• ✓ 30-day return policy
• ✓ Secure checkout with encrypted payment processing

Browse more AR Rifles or explore our Franklin Armory collection for additional binary-ready builds and parts.

Last updated: April 2026