Browning 12507 XLock Integrated Scope Mount (XBolt), 1" mount, .400" Standard, Nickel FinishSecurely mounted optics are essential to the accuracy and precision of any rifle. To ensure the new XBolt has the most stable mount possible, it features an all new XLock scope mounting system that uses four screws per base, replacing the traditional twoscrew system. The benefits are obvious, with the scope bases being secured at all four corners rather than only held at the center of the base, allowing for more accurate placement of the bases on the receiver. This revolutionary new XLock system holds the base tighter to the rifle than ever before.Integrated Scope Mounts unitize the ring and base into a single unit machined from 7000 series aluminum and eliminate alignment problems and possible loose connections between bases and rings Choose from integrated mounts in Standard, Intermediate and High rings for both 1" and 30mm diameter scopes in gloss, matte and nickel finishesFeaturesRing System Height SelectionUse the Standard (low) ring height for scopes up to a 44mm objective with a standard barrel contourUse the Intermediate (medium) ring height for scopes up to a 50mm objective with a standard barrel contourUse the High ring height for scopes up to a 56mm objective with a standard barrel contour