Cornerstone Lower fans have been asking for years now; "Does GGP make a forged upper with the same gorgeous anodizing and tight fit as their lower?" Ask and ye shall receive! Finally, you can grab what Grey Ghost Precision considers the best forged upper in the biz, and it is a perfect companion for your GGP Cornerstone Lower receiver. After all, accuracy comes from tight, precise tolerances that minimize all variables from the moment the hammer strikes the firing pin until the round leaves the muzzle. By perfecting the critical tooling dimensions to the smallest degree, a forged receiver can punch the same hole down range. Machined to tighter than Mil-Spec tolerances, Mfg: Grey Ghost Precision