Rock River Arms A4 Tactical Carbine Upper 458 SOCOM 16"
Complete upper receiver chambered in 458 SOCOM with 16" chrome moly barrel, RRA Operator muzzle brake, 15" free float M-LOK handguard, bolt carrier group, and charging handle. AR-15 compatible.
Fits: AR-15
Rock River Arms A4 Tactical Carbine Upper Receiver
This complete upper receiver assembly delivers serious capability in the potent 458 SOCOM cartridge. Rock River Arms has engineered a purpose-built platform for shooters who demand performance and reliability.
Specifications
- Caliber: 458 SOCOM
- Barrel: 16" chrome moly with 1:14 twist rate
- Configuration: A4 upper receiver
- Muzzle Device: RRA Operator brake (5/8-32 thread pitch)
- Handguard: 15" RRA free float rail with M-LOK attachment points
- Finish: Anodized black
- Compatibility: AR-15 platform
What's Included
This is a complete upper assembly—no additional parts required for installation on a compatible lower receiver:
- Bolt carrier group
- Charging handle assembly
- All components properly assembled and tested
Why This Upper Matters
The 458 SOCOM is a specialized cartridge designed for maximum stopping power at intermediate ranges. Rock River Arms' A4 configuration provides a proven platform that's been refined through years of tactical and sporting use. The free float design ensures consistent accuracy, while the M-LOK rail system offers modern accessory mounting flexibility.
The included Operator brake helps manage recoil while providing a professional appearance. This is a complete, ready-to-mount solution for AR-15 lower receivers.
Features
- .458 socom chamber
- 16-inch chrome moly bull barrel, 1:14 twist
- rra operator brake / 5/8–32 thread
- low profile gas block
- rra lightweight free float rail, 15 inch extended
- bolt carrier group and charging handle assembly
