The Rock River Arms LAR-BT3 Varmint in .308 Win/7.62x51mm NATO (MPN XBT31521) is a precision AR-10 platform rifle built around a 20-inch stainless steel bull barrel with a 1:10-inch twist, cryogenically treated for consistent accuracy. Rock River Arms machines the RRA BT-3 billet lower and A4 upper receivers, runs a low-profile gas block on a rifle-length gas system, and fits the RRA two-stage trigger for a clean, repeatable break. The rifle carries a 17-inch extended M-LOK-compatible free-float handguard, a Hogue rubber grip, and an RRA six-position NSP-2 CAR stock. Among AR-platform rifles in the AR rifles category, the LAR-BT3 Varmint favors long-range shooters who want a heavy bull barrel on a billet AR-10 platform.

Key Specifications

• Chambered in .308 Win/7.62x51mm NATO with a 1:10-inch rate of twist.
• Features a 20-inch stainless steel bull barrel, cryogenically treated.
• Runs a rifle-length gas system with a low-profile gas block.
• The lower and upper receivers are RRA BT-3 billet construction.
• Includes the RRA two-stage trigger.
• The handguard is a 17-inch extended, M-LOK-compatible free-float design.
• The grip is a Hogue rubber design.
• The stock is an RRA six-position NSP-2 CAR design.
• Feeds from a detachable magazine with a 20+1 capacity.

Frequently Asked Questions

Why a bull barrel? The heavier stainless steel profile resists heat and harmonics for tighter groups at range.

What trigger does this rifle use? The RRA two-stage trigger.

What are the receivers made from? RRA BT-3 billet construction, both upper and lower.

Buy the Rock River Arms LAR-BT3 Varmint .308 Win

A heavy bull barrel on a billet AR-10 platform is exactly what the LAR-BT3 Varmint delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.