Rock River Arms AR0598.V1 LAR-15M Upper | .223 Wylde | 18″ Barrel

This Rock River Arms AR0598.V1 LAR-15M is a factory complete AR-style upper built around an 18-inch stainless heavy match barrel chambered in .223 Wylde. The configuration combines a cryogenically treated match barrel, a 13-inch free-float M-LOK handguard, and an RRA Operator muzzle brake for a stable, tunable platform. It is intended for precision-oriented field use where a longer, heavy barrel benefits accuracy and barrel life.

Typical applications include precision target shooting and varmint/hunting work where a stabilized 18-inch barrel and a .223 Wylde chamber provide flexibility for both .223 Remington and 5.56 NATO-style loads.

Product Specifications

• The manufacturer is Rock River Arms.
• The part number is AR0598.V1.
• The product type is Complete Upper.
• The caliber is .223 Wylde.
• The upper receiver style is forged A4.
• The barrel measures 18 inches and is made of stainless steel and described as heavy match and cryogenically treated.
• The barrel twist rate is 1:8.
• The muzzle device is listed as the RRA Operator Muzzle Break.
• The muzzle thread is listed as 1/228 in the source data.
• The gas block type is a low profile gas block.
• The handguard is a 13 inch extended lightweight free float rail and is M-LOK compatible.
• The handguard finish is black.
• The overall finish type is black.
• The upper includes a bolt carrier group and charging handle assembly.
• The UPC is 842834101139.

This upper is built for shooters who prioritize a stable, accurate barrel profile and a modern free-float chassis for accessory mounting. The cryogenically treated heavy match barrel and 1:8 twist make it suitable for deliberate precision work and field varmint/hunting scenarios where consistent accuracy is important. The included bolt carrier group and charging handle make this a ready-to-install complete upper for compatible AR-pattern lowers.