Rock River Arms RRA CMPLT CAR A4 UPR .458 Socom 16″

Description

Rock River Arms’ complete A4 upper is chambered in .458 Socom and built to mate with AR-15 lower receivers for big-bore AR platforms. The assembly includes a 16″ chrome moly bull barrel with a 1:14 twist and comes factory-equipped with a complete bolt carrier group and charging handle. A 15″ lightweight RRA free-float M-LOK rail provides accessory mounting while the RRA Operator brake is threaded 5/8-32 for standard muzzle device options.

Key Specifications

• Chambering is .458 Socom.
• The barrel is a 16″ chrome moly bull barrel.
• The rifling twist rate is 1:14.
• Included with the upper is a complete bolt carrier group and charging handle assembly.
• The handguard is a 15″ RRA lightweight M-LOK free-float rail.
• The muzzle device is an RRA Operator brake with a 5/8-32 thread pitch.
• Platform fit is AR-15.
• The finish is Anodized in Black.

This factory-assembled A4 upper delivers a turnkey option for builders and shooters who need .458 Socom capability on an AR-15 platform. With a robust chrome-moly bull barrel, full-length free-float M-LOK rail and the included bolt carrier group and charging handle, it provides a practical, ready-to-integrate package for big-bore AR projects and field use.

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