The White Oak Armament Varmint in 5.56x45mm with a 20-inch barrel is a precision semi-auto AR-15 optimized for varminting and service rifle competition. WOA is known for their high-quality barrels and this rifle features their match-grade stainless steel barrel with 1:8 twist. Type: Semi-Auto Rifle Action: Direct Impingement Caliber: 5.56x45mm Capacity: 30 Year introduced: 2005, USA Weight: 9 oz Overall length: 38.5" Status: Active Intended use: Varminting, Competition, Range