EGW Guns Scope Base Features The EGW Guns Scope Base brings a one piece Picatinny scope rail to the Mossberg 100 ATR and 4x4 long action replacing a pair of separate scope bases with a single mounting surface that gives the shooter much more flexibility in eye relief and scope selection. Full width cross slots are gauged to MIL-STD 1913 specs to within plus or minus .002 inches so the rail reliably accepts a wide range of Picatinny and Weaver rings. The base is drilled to match the factory scope mount holes on the receiver so installation is a direct bolt on job with no drilling or tapping of the action needed. A milled center channel trims unnecessary material for a lighter mount without sacrificing the rigidity of the mounting surface. Machined from extruded aluminum alloy the base holds up to the recoil and handling of regular hunting and range use on a long action bolt rifle. At 7.458 inches overall and just 2 ounces it adds minimal bulk and weight while providing a stable rigid mounting platform for the scope. The ambidextrous design suits left and right handed shooters alike and EGW includes number 6-48 by 1/4 inch screws along with a T-10 bit for installation recommending 20 inch pounds of torque with a drip of blue thread locker. This Picatinny rail base is a practical affordable upgrade for Mossberg 100 ATR and 4x4 long action owners looking to modernize their scope mounting setup. EGW Guns Scope Base Specifications Manufacturer: EGW Guns Model: Scope Base Type: Picatinny Scope Base Compatible Hosts: Mossberg 100 ATR/4x4 Long Action Color: Black Material: Aluminum Alloy Elevation: 0 MOA Mount Type: Picatinny Rail Center Spread: 4.7 Overall Length: 7.458 Height: .575 Weight: 2 oz Handedness: Ambidextrous Available At: GrabAGun