The Ruger SR556 is a piston driven rifle, developed on the AR 15 platform, intended on increasing reliability. This example is the SR556 TV “Varmint” variant, using a 20″ stainless steel barrel. This rifle has also received a number of upgrades including a Millett scope, match grade trigger and adjustable Luth AR stock. Unfortunately the adjustable length of pull is classified as “Telescoping” in the state of NJ, so be sure of state and local laws before purchase.