Precision-drilled 5.5mm safety-stops are milled into the rails along both edges of the rail for ambidextrous use. The R-LOCK holes, positioned at least 10mm apart, provide multiple safety-stop locations along the rail at a tightly controlled distance from the edges.
The R-LOCK hole positioning also accommodates centrally-located mounting features and traditional safety-stop mechanisms while maintaining backward compatibility. The geometry was optimized for manufacturing in 6061-T6 aluminum (though harder alloys may be used) and can be milled by any machinist or gunsmith without requiring a CNC mill.
The USR features a modular slotted mounting system, offering a wide range of compatibility across multiple types of devices and mounting systems. RRS offers four different hardware kits: One for wood and composite stocks, a second for chassis systems with tapped holes, the third for Accuracy International's Key Slot system, and finally M-LOK compatibility. The different anchors can slide within the rail slots and are held captive with an o-ring. Additional hardware kits can be purchased if the user desires interchangeability or additional mounting points. For more details on what is included with each hardware kit, click on the different mounting hardware options above and check out the "What's in the box" section of the page.
Note: The USR is a low-profile, lightweight system. The rail is not designed to be cantilevered out beyond the foregrip of a rifle. A minimum of one anchor per slot on the rail is required for adequate support, equally distributed. The rail needs to be installed on a flat surface and not all gunstocks are equally flat. Mounting to a surface that is not perfectly flat will result in a bow in the rail and lead to inconsistent performance of the clamp. Due to the universal fitment of this rail system, Really Right Stuff is not responsible for the bending or deformation of the rail due to improper installation or use.
All Really Right Stuff brand products are guaranteed to the original purchaser to be free of defects in materials or workmanship for five (5) years from the date of purchase. Product will be repaired or replaced at our option.