The Atlas BT79 Picatinny Rail Mount Barret M107A1 Black is a 5-slotted 1913 Picatinny rail for direct installation to the Barrett M107A1 providing the means to mount our Atlas Bipod Picatinny rail mounted bipods. The center-to-center hole spacing of 3.359" fits the outer two holes of the existing three holes in the chassis. We strongly suggest that you measure the hole spacing on your rifle. The center section is machined to Picatinny rail standards from 4140 cold finished steel with a maganese phosphate finish. Two 3/8-16 x 3/4" flat head cap screws are provided. The original 11/16" nuts and tooth lock washers are reused to complete assembly. An 11/16" socket and ratchet wrench OR break-over bar and a 7/32" hex wrench is required for installation (none included). Check out installation instruction below. No modification needed.Overall Length: 4.309"Weight: 5.22 ouncesFeatures5-slotted 1913 Picatinny rail for Barrett M107A1Overall Length: 4.309"...