Description
The USR™ Upper Standard Receiver is a precision machined upper with a special proprietary bore that is ultra smooth with a roughness average in micro inches of 16, as opposed to standard bored or milled uppers that are 32-63, or higher.This reduces bolt carrier friction and creates a much smoother operation.Barrel nut threads, bore and barrel extension surfaces are all machined in one operation so that they areperfectly concentric and perpendicular to the barrel and fixing assembly.
Specification:
Material: Billet 7075-T6 AluminumFinish: Milspec Type3, Class2 Deep Black Hardcoat Anodize.Super smooth Bore.M4 Feedramps as standard.
Made in the USA.
Stripped Weight 7.0oz (197g).
