Picatinny cross-section aluminum rail stock gives you a head start on building custom scope bases. Extruded from 6061 Aluminum to the tolerances of Mil-STD-1913. Pre-contoured, so you need only cut to required length, mill cross-slots, radius the underside (if needed), and drill mounting holes. Much easier than machining from scratch from bar stock. Perfect for installations that require special ring positioning. Place cross-slots only where you need them; dovetail contour accepts Picatinny or Weaver-style rings. We offer black rails up to 12 foot lengths. For slotted rails we can offer 12 inch, 24 inch and 36 inch pieces.