The Rock River Arms LAR-BT3 Varmint is a semi-automatic rifle chambered in .308 Win with a 20-inch bull barrel and a 1:10" twist rate. It uses direct impingement gas operation and runs from a detachable box magazine with 20+1 capacity. The overall length adjusts between 37.25" and 39.75" via the RRA 6-position NSP-2 carbine stock. 
 

Key Specifications 

• Model: LAR-BT3 Varmint 
• Caliber: .308 Win 
• Action: Semi-Auto 
• Barrel Length: 20 inches 
• Capacity: 20+1 rounds 
• Overall Length: 37.25" - 39.75" 
• Weight: 9.80 lbs 
• Safety: Safety Selector Switch 
• Stock Description: RRA 6 Position NSP-2 Carbine 
• Finish Color: Black 
   

Detailed Features 

The bull barrel adds rigidity and thermal mass, which helps maintain accuracy through extended strings of fire. The high-quality aluminum receiver keeps the overall weight from being excessive despite the heavy barrel. A safety selector switch is the standard AR-pattern control layout. 
 
At 9.80 lbs., the LAR-BT3 Varmint is bench and supported-position oriented. It is a practical choice for varmint control at distance or for .308-class accuracy work where a heavy barrel is desirable.

The Rock River Precision LAR-BT3 Varmint in .308 Win with a 20-inch barrel gets solid marks from precision shooters and varmint hunters.

Accuracy is the most praised attribute. The bull barrel and 1:10" twist rate deliver tight groups at long range, and users report consistent results across a range of .308 factory loads. Build quality is generally well-regarded; the construction feels solid and inspires confidence over extended use.

The .308 recoil is noted by some as noticeable but manageable, particularly in a supported shooting position where the rifle is most commonly used. Ergonomics receive favorable feedback, and the adjustable stock is cited as helpful for fitting different shooters.

Customization discussions come up regularly since it accepts standard AR-10-pattern accessories. Price is a reasonable point of discussion; most owners consider it fair given the precision-focused feature set, though comparisons with budget alternatives appear in threads. Customer service interactions with Rock River Arms vary among users.