This superbly accurate Assembly - from Windham Weaponry Varmint Exterminator Rifle - is ready for the range or varmints. Precision machined from 416R Stainless Steel, it includes a matched bolt and carrier machined from Carpenter 158 Steel. It is machined to mate with the Compass Lake specification Chamber for highest possible accuracy. The barrel is matte finished to avoid reflective glare, and is fluted to reduce weight, increase barrel surface and add rigidity. A Picatinny Rail Gas Block is included should you want to attach a front sight, as are 1/2" high "mini-risers" for the easy attachment of a scope or optic. Button rifling is 1 turn in 8" - right hand twist for optimum accuracy with a wide range of heavier .223 Rem. / 5.56mm NATO varmint bullets.