Volquartsen stainless steel drop-in 0.920" bull barrels set the standard in accuracy and performance for rimfire barrels. They feature match bore and chamber dimensions and vary no more than +/- 0.0001" from breech to muzzle. Each barrel is digitally measured and inspected.The barrel shank is machined 0.0025" oversized to create an extremely tight fit into the factory receiver. This prevents the barrel from canting once the locking block is installed. Volquartsen developed a unique chamber to provide optimal accuracy but also superior function. Summit barrels feature a machined ramp making for a smooth transition from magazine to chamber when cycling the straight-pull action. Features0.920" diameterThreaded 1/2" X 28Thread Protector