Concerning the article titled “Building an 80% Firearm,” I just wanted you (and the readers, should you decide to post this) to know that the 80% handgun market is continuing to expand. In addition to the Not-A-Glock and 1911s, there is a website (matrixprecisionparts.com) that offers 80% Sigs for construction. On the website, they also sell refinished German Sig Sauer P228 9mm parts kits for the 80% receiver. This is easily one of the most satisfying builds I have done. Now if only someone would offer an 80% M1A or mini 14 receiver and tooling. – F.M.