The Rock River Arms LAR-15 Operator ATR Carbine is an AR-pattern semi-automatic rifle chambered in 5.56 NATO with a 16-inch barrel. It ships with a 30-round magazine and has a 6-position adjustable stock. The synthetic furniture is finished in black throughout. 
 

Key Specifications 

• Brand: Rock River Arms 
• Model: LAR-15 Operator ATR Carbine 
• Caliber: 5.56 NATO 
• Action: Semi Auto 
• Barrel Length: 16 inches 
• Capacity: 30 rounds 
• Color/Finish: Black 
   

Detailed Features 

• 16-inch barrel in a standard carbine-length configuration 
• 6-position adjustable stock 
• Synthetic stock and furniture in black 
• 30-round magazine included 
• AR-15 pattern (LAR-15) platform

Rock River Arms LAR-15 owners frequently mention the quality of the upper receiver machining and the fit between the upper and lower. The Operator ATR Carbine is a no-frills working rifle, and buyers who want a reliable range carbine without spending on premium components tend to be satisfied with what they get.

The 6-position stock is a standard mil-spec unit, which means it works well enough and takes any mil-spec replacement easily. The 16-inch barrel is a practical length for general use, and the all-black synthetic setup keeps the rifle straightforward to maintain.

Trigger feel is the most common complaint. The stock trigger is described as heavy and gritty by most owners, and aftermarket upgrades are a frequent first mod. Beyond that, reliability complaints are uncommon, and the platform is considered a solid mid-tier AR build.