The Rock River Arms LAR-BT3 Operator DMR is engineered as a purpose-built Designated Marksman Rifle, delivering precision and robust performance in a .308 Winchester AR-platform. Designed for discerning shooters who require consistent accuracy and reliable operation, this system integrates high-quality components for sustained engagement and tactical utility.
Key Features
Precision-Engineered Receiver
The LAR-BT3 utilizes a billet aluminum receiver set, machined for enhanced structural integrity and precise component fit. This construction minimizes flex and contributes to the system’s inherent accuracy potential, providing a solid foundation for all integrated components.
Optimized Barrel System
Features a 20-inch barrel, selected to maximize velocity and terminal performance for the .308 Winchester cartridge. The barrel profile is optimized for a balance of weight, heat dissipation, and repeatable accuracy, supporting extended shot strings without significant point-of-impact shift.
Integrated Handguard System
Equipped with a 17-inch lightweight M-Lok free-float handguard. This system provides extensive modularity for accessory integration while maintaining a slim profile, facilitating a secure and comfortable grip. Its free-float design ensures barrel harmonics are unaffected by accessory mounting or shooter input, preserving accuracy.
Enhanced Ergonomics & Control
The BCM SOPMOD stock offers multiple adjustment positions for length of pull, providing a stable cheek weld and comfortable shooter interface. A Hogue Beavertail Grip ensures positive weapon control and mitigates hand fatigue during prolonged use. The OEM Match Trigger is factory-tuned to provide a crisp, predictable break, enhancing shot placement precision.
Robust Sighting Solution
Includes Magpul MBUS Pro sights, offering a durable and reliable backup or primary sighting system. These low-profile, all-steel sights provide a precise sight picture and maintain zero under demanding conditions.
Reliability and Durability
Finished in a non-reflective black, the LAR-BT3 is constructed to withstand rigorous use. Each component is selected for its proven performance and contribution to the rifle’s overall system reliability. A hard case is included for protected transport and storage.
Technical Specifications
- Model: Rock River Arms OP1005BT LAR-BT3 Operator DMR
- Caliber: .308 Winchester
- Capacity: 20+1 Rounds
- Barrel Length: 20 inches
- Receiver Material: Billet Aluminum
- Stock: BCM SOPMOD
- Handguard: 17-inch M-Lok Lightweight Free-Float
- Grip: Hogue Beavertail
- Sights: Magpul MBUS Pro Flip-Up
- Trigger: Rock River Arms OEM Match
- Finish: Black
- Included: Hard Transport Case









