Rock River Arms | Tactical Carbine A4 Upper | .458 SOCOM | 16-inch

The Rock River Arms Tactical Carbine A4 complete upper is an AR-15 compatible assembly chambered in .458 SOCOM and built around a 16-inch chrome moly bull barrel with a 1:14 twist. It ships as a ready-to-install upper with a complete bolt carrier group and charging handle assembly. The upper features a 15-inch RRA lightweight free-float rail that accepts M-LOK accessories and an RRA Operator brake with 5/8-32 threading. The configuration suits users who need a big-bore AR-15 upper for short-range heavy-bullet work and large-game hunting where .458 SOCOM is appropriate.

Product Specifications

• The manufacturer is Rock River Arms.
• The model is listed as Tactical Carbine.
• The product type is Upper.
• This upper is designed to fit AR-15 receivers.
• The caliber is .458 Socom.
• The barrel length is 16-inch.
• The barrel is a chrome moly bull profile.
• The rifling twist rate is 1:14.
• An included component is a complete bolt carrier group.
• A charging handle assembly is included.
• The handguard is a 15-inch RRA lightweight free-float rail that is M-LOK compatible.
• The muzzle device is a RRA Operator brake with a 5/8-32 thread pitch.
• The finish is Anodized and the color is Black.
• The subcategory is Complete Upper Receivers.
• The UPC is 842834111916.

This complete A4 upper provides a straightforward, factory-configured solution for operators and enthusiasts who require a heavy-caliber AR-15 upper ready for installation. With its 15-inch free-float M-LOK rail and included bolt carrier group and charging handle, it simplifies the build process while retaining modularity for optics and accessory selection.