Introduced in 2007,[11] the "Target Rifle" version has a 22-inch (560 mm) cold hammer-forged heavy barrel, adjustable harmonic tuner with adjustable minute-of-angle accuracy, and either a laminated wood or Hogue overmolded synthetic stock.[12][13] The Target Rifle does not have iron sights but includes the standard scope rings and Picatinny rail mount.[13] It is designed for use with the .223 Remington round only; 5.56 NATO is not warranted by Ruger.[14]