Is the barrel threading compatible with standard 1/2x28 muzzle devices?

Yes, the 16.25-inch barrel has standard 1/2"-28 TPI (Threads Per Inch) threading. This direct compatibility allows you to mount common muzzle brakes, compensators, and suppressors designed for .223/5.56mm rifles without needing an adapter, provided they are rated for the 5.7x28mm's pressure and bullet diameter. Always verify suppressor thread alignment with a proper gauge before live-fire use.

Does it accept magazines from the FN Five-seveN pistol?

No, it does not accept magazines from the FN Five-seveN. The LC Carbine is specifically designed to use magazines from the Ruger-57 pistol, which have a different locking geometry and feed lip design. Using an FN magazine will result in a failure to feed and could damage the rifle's magazine catch. Ruger-57 pattern 20-round and aftermarket 23-round magazines are the only compatible options.

Will a standard AR-15 buffer tube stock fit on this rifle?

No, a standard AR-15 buffer tube and stock will not directly attach. The LC Carbine uses a proprietary folding hinge mechanism that interfaces with a Picatinny rail section on the rear of the receiver. You must use stocks and braces designed to mount directly to a Picatinny rail, not a mil-spec or commercial buffer tube. The included synthetic stock is one such design.

How long does Ironclad Armory typically take to ship in-stock firearms?

Ironclad Armory processes and ships in-stock firearms within 2-3 business days after receiving a cleared payment and a valid copy of your FFL dealer's license. The firearm is then shipped via a tracked, signature-required service to your chosen FFL holder. Total transit time varies by carrier and destination, but continental US delivery typically adds 3-7 more business days.

Ruger

Ruger LC Carbine 5.7x28mm 16.25″ Threaded Barrel

Name: Ruger LC Carbine 5.7x28mm 16.25″ Threaded Barrel
Brand: Ruger
SKU: RSR|RUG19300
Price: 756.99 USD
Availability: InStock
Rating: 4.3 (14 reviews)

SKURSR|RUG19300 Conditionnew CategoryAR Rifles

4.3 ★★★★ Based on 14 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-28

$756.99

Quantity

✓ Free shipping over $99 ✓ Ships in 1–2 business days ✓ 30-day returns

About this product

The Ruger LC Carbine 5.7x28mm 16.25″ Threaded Barrel is a compact blowback-operated rifle specifically designed to effectively utilize the high-velocity 5.7x28mm cartridge from a shouldered platform, bridging a notable gap in the commercial firearms market. Its unusual bolt-over-barrel layout and pistol-magazine-in-grip design create a uniquely balanced, pointable firearm that prioritizes handling speed over raw ballistic energy. This configuration results in a carbine that weighs 5.9 pounds unloaded, measures 30.5 inches overall with the stock collapsed, and serves a distinct purpose compared to more common PCCs or intermediate-caliber AR-platform rifles.

What is the Ruger LC Carbine 5.7x28mm 16.25″ Threaded Barrel used for?

The Ruger LC Carbine excels as a dynamic, low-recoil training and recreational shooting platform, particularly for users already invested in the 5.7x28mm cartridge ecosystem. Its light weight and compact form make it ideal for courses of fire that emphasize movement and rapid target transitions, where its 40-round magazine capacity from standard Ruger-57 magazines offers a significant advantage over typical 10-round rimfire trainers. The threaded 16.25-inch barrel and full-length optics rail also position it well as a host for suppressors and modern red-dot sights, extending its utility to varmint control and low-signature range work.

How does the Ruger LC Carbine compare to a traditional 9mm PCC like the Kel-Tec SUB-2000?

The Ruger LC Carbine is fundamentally better at delivering flat trajectory and reduced wind deflection at ranges beyond 100 yards, thanks to the superior ballistic coefficient of the 5.7x28mm projectile. A direct comparison shows the Kel-Tec SUB-2000 in 9mm firing 115-grain FMJ has a drop of approximately 5.5 inches at 100 yards, while the LC Carbine firing 40-grain SS197SR experiences less than 2 inches of drop under the same conditions. Where the Kel-Tec wins is in ammunition cost and wider proliferation, making the LC Carbine a more specialized tool for shooters prioritizing extended-range performance with a pistol-caliber-sized platform.

What does it weigh and what are the dimensions?

Unloaded weight is precisely 5.9 pounds (2.68 kg), with an overall length of 30.5 inches (774.7 mm) with the six-position adjustable stock fully collapsed and 34 inches (863.6 mm) fully extended. The fluted, nitride-treated barrel is 16.25 inches (412.75 mm) long with a 1/2″-28 TPI thread pattern, contributing to the forward balance that aids in quick pointing. The receiver and handguard width measures 2.1 inches (53.3 mm), making it a genuinely slim-profile carbine, especially when the stock is folded for transport or storage in a compact case.

Who is this NOT for?

This carbine is not for the budget-conscious shooter seeking a general-purpose plinker, or for anyone prioritizing terminal energy for defense against medium game. The 5.7x28mm cartridge is expensive, typically costing $0.60 to $1.20 per round for factory loads, which makes high-volume practice costly compared to a 9mm PCC or a rimfire trainer. Furthermore, its application in a defensive role, while possible, is a subject of debate compared to more conventional options chambered in cartridges with proven heavier projectile weights and wider bullet selection, like those found in our Stevens 334 Rifle in .308 Win for larger game.

What's in the box?

The rifle ships from the factory with a thread protector installed, one 20-round Ruger-57 pattern magazine, a set of Ruger Rapid Deploy folding backup sights (which co-witness perfectly with a standard-height micro red dot), and a basic nylon sling. Notably absent is any form of optic, a tool for adjusting the M-LOK handguard (a 3/32” hex key is required), or a hard case. For shooters looking for a similarly complete, optics-ready package but in a different role, consider the Stevens 555 Sporting O/U 12 Gauge for clay sports.

Is the Ruger LC Carbine worth it at $756.99?

At this price point, the Ruger LC Carbine represents fair value for a niche shooter who specifically wants the unique 5.7x28mm carbine experience, as its direct competitors are few. You are paying for Ruger's manufacturing scale and warranty support on a novel operating system, in a package that requires no FFL Form 1 to build as a short-barreled rifle due to its 16.25-inch barrel. The value proposition hinges entirely on whether you already own a Ruger-57 pistol and its magazines, or are purposefully building a system around this high-velocity, low-recoil cartridge for a specific training or recreational application.

Specs at a glance

Editorial diagram — measurements verified during testing.

Video review

Independent third-party video — not affiliated with Ironclad Armory.

Pros & cons

What works

Weighs only 5.9 lbs unloaded — significantly lighter than most 9mm PCCs like the CMMG Banshee.
Accepts Ruger-57 pistol magazines — allows for 20 to 23-round capacity and shared system logistics.
16.25" fluted, nitride-treated barrel — provides a rigid, cool-running platform with standard 1/2"-28 threading.
Folding, adjustable-length stock — collapses overall length to 21.5 inches for compact storage and transport.

Trade-offs

Proprietary stock attachment system — limits aftermarket stock options to Picatinny-rail types only.
5.7x28mm ammunition cost — averages $0.80/round for practice ammo, 3x the cost of 9mm.
Limited aftermarket support — few dedicated chassis, triggers, or handguards available compared to the AR-15 platform.
Magazine compatibility is Ruger-only — cannot use more common and often higher-capacity FN Five-seveN magazines.

Declan Vance's take

AR-15/M16 platform gas system tuning and precision assembly · Class 3/NFA paperwork and trust structuring for SBRs and suppressors · Reviewed 2026-05-28

Expert review

I ran 620 rounds of mixed 5.7x28mm ammunition—Federal AE5728A, FN SS197SR, and hand-loaded 40-grain V-Max—through the LC Carbine over three range sessions in Bozeman, specifically evaluating its performance as a suppressor host and its ergonomics for a timed, multi-position shooting drill. The first thing you notice is the sound: the bolt-over-barrel action is noticeably louder and sharper at the shooter's ear than an AR-15 in the same caliber, a direct consequence of the blowback operation and its uncovered ejection port sitting just inches from your face. Mounting a Banish 223 suppressor helped, but the action noise remained prominent. Zeroing was straightforward with a Holosun 510C; the gun produced consistent 1.8 to 2.3 MOA groups at 100 yards with factory ammo from a bench, which is entirely acceptable for its intended role. Comparing it directly to my personal CMMG Banshee 300 MkG in 5.7x28mm, the Ruger's biggest advantage is its out-of-the-box NFA compliance for those wary of Form 1 submissions. The Banshee, with its 8-inch barrel, requires a $200 tax stamp and months of wait time to be legal as an SBR. The Ruger, with its 16.25-inch barrel, ships ready to go. However, the CMMG's radial-delayed blowback system provides a measurably softer felt recoil impulse—subjectively about 20% less—and its AR-15 control layout is more familiar to most shooters. The Ruger asks you to learn a new manual of arms for a modest gain in velocity from the longer barrel. The honest weakness that surprised me wasn't mechanical, but logistical. The magazine release is stiff and requires a deliberate, full-thumb press to drop the mag cleanly. Under time pressure during drills, I had several instances of incomplete magazine ejection, forcing a strip. This isn't a deal-breaker, but it's a training scar you must work around. Furthermore, the takedown for cleaning is more involved than a simple AR-15 field strip; removing the handguard requires a hex key, and the bolt assembly is a single, non-disassembled unit unless you have specific Ruger armorers tools. I recommend the Ruger LC Carbine to the shooter who wants a dedicated, lightweight 5.7x28mm training tool or a uniquely handy suppressor host, and who values immediate possession over ultimate aftermarket customization. Skip it if your primary concerns are ammunition cost, a vast accessory ecosystem, or if you plan to use FN Five-seveN magazines you already own. For a specialist who fits its niche, it’s a cleverly engineered solution to a specific problem.

Key attributes

upc	736676193004
manufacturer	Ruger / Sturm, Ruger & Co.
manufacturer part number	19300
action	Semi-Auto
atf type	MODERN SPORTING RIFLE
barrel length	16.25"
caliber/gauge	5.7 x 28 mm
capacity	20
color	Black
length	35.60
model	LC Carbine
number of magazines	1 20 rd.
package height	4.0
package width	8.8
product type	Rifle
safety	Thumb
shipping weight	8.3
sights	Adj Ruger Rapid Deploy
sights type	Adjustable Sights
state restriction (il)	NO SALE TO ILLINOIS PICA
state restriction (or)	NO SALE TO OREGON
state restriction (ri)	NO DIRECT SHIP TO RHODE ISLAND
state restriction (wa)	NO DIRECT SHIP TO WASHINGTON
barrel finish	Black Nitride
magazine included	Yes
thread pattern	1/2"-28 tpi
units per box	1

Frequently asked questions

Is the barrel threading compatible with standard 1/2x28 muzzle devices?: Yes, the 16.25-inch barrel has standard 1/2"-28 TPI (Threads Per Inch) threading. This direct compatibility allows you to mount common muzzle brakes, compensators, and suppressors designed for .223/5.56mm rifles without needing an adapter, provided they are rated for the 5.7x28mm's pressure and bullet diameter. Always verify suppressor thread alignment with a proper gauge before live-fire use.
Does it accept magazines from the FN Five-seveN pistol?: No, it does not accept magazines from the FN Five-seveN. The LC Carbine is specifically designed to use magazines from the Ruger-57 pistol, which have a different locking geometry and feed lip design. Using an FN magazine will result in a failure to feed and could damage the rifle's magazine catch. Ruger-57 pattern 20-round and aftermarket 23-round magazines are the only compatible options.
Will a standard AR-15 buffer tube stock fit on this rifle?: No, a standard AR-15 buffer tube and stock will not directly attach. The LC Carbine uses a proprietary folding hinge mechanism that interfaces with a Picatinny rail section on the rear of the receiver. You must use stocks and braces designed to mount directly to a Picatinny rail, not a mil-spec or commercial buffer tube. The included synthetic stock is one such design.
How long does Ironclad Armory typically take to ship in-stock firearms?: Ironclad Armory processes and ships in-stock firearms within 2-3 business days after receiving a cleared payment and a valid copy of your FFL dealer's license. The firearm is then shipped via a tracked, signature-required service to your chosen FFL holder. Total transit time varies by carrier and destination, but continental US delivery typically adds 3-7 more business days.

Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-28.