Brand: Rock River Arms
Model: Lar-15M, NM A4
Caliber: .223 Wylde
Platform: AR-15
Barrel: 20" Air Gauged Heavy Stainless Steel Cryogenically Treated
Gas System: Rifle Length
Muzzle Device: A2 Flash Hider
Muzzle Thread: 1/2-28
Twist: 1:8
Receiver: Forged A4, Black
Handguard: 12.5" RRA National Match Aluminum Free Float
Attachment Style: M-Lok
BCG: Yes
Charging Handle: Yes

Features

Built for precision and performance, this upper receiver assembly is chambered in .223 Wylde, making it compatible with both 5.56mm NATO and .223 Remington cartridges. It features a 20-inch air-gauged, heavy match-grade stainless steel barrel with a 1:8 twist, cryogenically treated for improved stability and longevity.

The A2 flash hider sits atop 1/2x28 threads, while a gas block sight base handles gas system duties. A 12.5-inch RRA National Match CMP TRO aluminum free-float handguard offers excellent rigidity and heat resistance, and comes equipped with three 11.625-inch modular NM TRO rail sections for accessory mounting.

This complete upper includes a forged A4 upper receiver, as well as a bolt carrier group and charging handle assembly, making it ready to pair with your favorite lower.

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Shipping Restrictions

It is the customer’s responsibility for understanding state laws regarding all purchases made. For a comprehensive list of all Shipping Restrictions, please refer to our Shipping Restrictions By State Page found Here.

All NFA Rules Apply

These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Local Law Compliance

Certain firearm parts and accessories, including AR-style upper receivers, are subject to complex and frequently changing federal, state, and local laws and regulations. While an upper receiver may be lawfully sold and shipped as a component, the legality of possessing, assembling, configuring, or using an upper receiver in certain states (e.g., California, Washington State) and localities depends on how it is assembled, combined with other components, and ultimately used. You are solely responsible for ensuring that any assembly, configuration, possession, or use complies with all federal, state, and local laws, including any so-called “assault weapon” bans and short-barreled rifle restrictions. We do not provide legal advice and are not responsible for unlawful configurations or uses.