Criterion complete upper receivers provide the perfect fit for a service rifle AR-15 build. These hand-crafted uppers are offered exclusively through Creedmoor Sports. A number of custom components enable this upper to perform well beyond the standards set by other manufacturers:
Included is a 20” free-floating Criterion 1-7.7 twist barrel chambered in .223 Rem Match. This chamber can accept both .223 Rem and 5.56 NATO ammunition. This configuration is tailored to improve the accuracy of heavier 80 gr. bullets without negatively impacting the performance of lighter ammunition. The cartridge OAL is 2.50” with a 80 gr. Sierra bullet. Hand lapped and button rifled with a service rifle contour, these barrels can be fitted with or without an A2 birdcage flash hider.
These hard coated anodized aluminum receivers feature a fixed A2 style carrying handle mounting a triple pinned ¼ x ¼ minute National Match rear sight. A 72 t.p.i windage screw allows for 10 clicks per revolution windage. Fine adjustment capability and elimination of sight wobble enables unparalleled consistency for distance shooting.
The .062 ramped front sight post features a jam screw to fix elevation adjustments. Half-moon barrel indents are specifically machined to mate with the included windage adjustable Bushmaster front sight. Rear sight internal diameter is .315 for mounting lense attachments.