The Bolt Tune-Up kit for the Ruger 10/22 includes the SureStrike firing pin and the Exact Edge extractor. Both of these upgrades increase the reliability of your stock 10/22. The SureStrike firing pin is designed to eliminate light primer strikes in Ruger 10/22 rifles. EDM machined from A2 tool steel and hardened to Rc56-58 for long term durability. The firing pin is also .004" wider than the factory pin to eliminate side to side movement. The Exact Edge extractor is a machined using an EDM process which creates precise tolerances that are not found in stamped extractors. The sharp hook of the Exact Edge is closer to the rim of the cartridge allowing for more positive extraction. The extractor is also made from A2 tool steel and hardened to Rc58-60 to maintain the sharp point with years of use.