Trying to figure out which parts are needed to take the Ruger MK IV or MK IV 22/45 to the next level? Look no further than the Pistol Competition Kit. This kit includes our Accurizing Kit for the Ruger MK IV Pistol and Bolt Tune-Up Kit for MKI, MKII, MKIII, MK IV, and 22/45 The Pistol Competition Kit is designed to produce a crisp, clean 2.25 trigger pull, eliminate stovepipes, and eliminate failures to fire!