The Rock River Arms LAR-15M NM A4 Complete Upper, .223 Wylde, 20" Stainless Heavy Match Barrel, Black Receiver, 12.50" M-LOK Handguard, Railed Gas Block, A2 Flash Hider (AR0784, UPC 842834100125) is a precision-focused AR-15 upper built for shooters who want National Match accuracy and rock-solid reliability right out of the box. Designed to pin onto any mil-spec AR-15 lower, this complete upper is ideal for CMP/NRA service rifle competition, precision target work, and serious varmint or predator hunting. Ready Gunner+2LG Outdoors Website+2
Match-Grade .223 Wylde Chamber – Shoot 5.56 & .223 with Confidence
This upper is chambered in .223 Wylde, a hybrid match chamber that safely fires both .223 Remington and 5.56 NATO while optimizing accuracy. The Wylde design features a slightly longer freebore than .223 match chambers combined with tighter dimensions than standard 5.56 NATO, giving you: rockriverarms.com+2rockriverarms.com+2
Improved accuracy potential with quality .223 match ammo
Full compatibility with 5.56mm NATO loads for training or duty use
Reliable extraction thanks to a chamber relieved in the case body and tuned throat geometry
If you want one upper that can handle common 5.56 loads and precision .223 match ammo, .223 Wylde is the sweet spot.
20" Air-Gauged Stainless Heavy Match Barrel – Built for Precision
The heart of the AR0784 is a 20-inch air-gauged heavy match stainless barrel made from 416R stainless steel. Each barrel is hand-lapped and cryogenically treated to enhance consistency, reduce internal stresses, and extend barrel life. rockriverarms.com+2rockriverarms.com+2
Key barrel details:
Length: 20" – classic rifle-length for maximum velocity and a longer sight radius (if irons are used)
Profile: Heavy match barrel for rigidity and repeatable harmonics
Material: 416R stainless steel for corrosion resistance and durability
Treatment: Air-gauged and cryogenically treated to tighten tolerances and maintain accuracy over long strings of fire rockriverarms.com+1
Twist Rate: 1:8" – optimized to stabilize popular bullet weights from ~55 to 77 grains, ideal for match and duty loads rockriverarms.com+2rockriverarms.com+2
This combination delivers match-grade accuracy capability, making it an excellent choice for service rifle competition and precision-focused AR builds.
A2 Flash Hider & Railed Gas Block
On the muzzle, Rock River Arms uses a classic A2 flash hider threaded to the barrel at 1/2x28, reducing visible muzzle flash and allowing easy swapping to other 1/2x28 devices or suppressor mounts if desired. rockriverarms.com+2rockriverarms.com+2
The upper also features a railed gas block / gas block sight base, giving you flexibility in sighting setups: Ready Gunner+2LG Outdoors Website+2
Mount a front iron sight to pair with a rear BUIS or detachable carry handle
Use the top rail for lasers or other low-profile accessories
Maintain a clean, rigid gas system under the free-float handguard
12.50" RRA NM CMP TRO Aluminum Free-Float M-LOK Handguard
This LAR-15M NM A4 upper comes with Rock River’s 12.5" aluminum rifle-length free-float handguard, often listed as the RRA NM CMP TRO rail. Ready Gunner+2alpinerange.com+2
Handguard benefits:
Free-float design – the handguard never contacts the barrel, helping preserve accuracy when using slings, bipods, or barricade rests.
Approx. 12.50" rifle-length – gives a long, stable support-hand position and plenty of mounting space. Ready Gunner+1
Configured with M-LOK style modular rail sections so you can add only the rail where you need it (bipod, light, QR sling, etc.) instead of carrying unnecessary weight. alpinerange.com+2LG Outdoors Website+2
The combination of a heavy match barrel and a true free-float handguard makes this upper well-suited to tight groups and consistent performance in demanding match conditions.
Forged A4 Flat-Top Upper – Mil-Spec Ready
The forged A4 upper receiver is hard-anodized in black and built to mil-spec dimensions, meaning it will pin onto virtually any quality AR-15 lower receiver. rockriverarms.com+2LG Outdoors Website+2
Features include:
Flat-top Picatinny rail for mounting optics, BUIS, detachable carry handles, or scope mounts
Rock River’s proven LAR-15M receiver geometry for reliable function and solid lock-up
Clean, black finish that matches most AR lowers and accessories
Whether you’re building a competition gun or upgrading a range rifle, this upper is ready for whatever glass or optics setup you prefer.
Complete Upper – Includes BCG & Charging Handle
The AR0784 is sold as a complete upper assembly, so you’re not left hunting for extra parts: Buds Gun Shop+3Ready Gunner+3alpinerange.com+3
Just attach this upper to your mil-spec lower, verify headspace and function, add sights or an optic, and you’re ready to hit the range.
.223 Wylde – Why It Matters for Accuracy
Rock River Arms built this upper specifically around the .223 Wylde match chamber, which offers: LG Outdoors Website+3rockriverarms.com+3rockriverarms.com+3
Match-grade throat geometry for improved accuracy versus a typical 5.56 NATO chamber
Safe operation with both 5.56mm NATO and .223 Rem ammo
A chamber relieved in the case body to aid extraction, ideal for high-round-count training or competition
When paired with the air-gauged, hand-lapped heavy barrel and a capable trigger in your lower, this upper is easily capable of sub-MOA performance with quality ammunition and good fundamentals (inferred from Rock River’s NM A4 rifle specs). rockriverarms.com+1
Ideal Applications – Who Is This Upper For?
The Rock River Arms LAR-15M NM A4 Complete Upper AR0784 is an excellent fit for:
Key Specs – Rock River Arms LAR-15M NM A4 Complete Upper (AR0784)
If you’re building or upgrading an AR-15 for National Match, precision target shooting, or serious varmint work, the Rock River Arms LAR-15M NM A4 Complete Upper, .223 Wylde 20" Stainless Heavy Match, AR0784 delivers match-grade components, proven Rock River quality, and ready-to-run completeness in one high-performance package.
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