The Hornady Lock-N-Load AP Progressive Press Case Retainer Spring is a handy replacement part for your Lock-N-Load AP press. One of the features that makes the Hornady Lock-N-Load AP an exceptional value is the ability to quickly and easily remove and replace a case at any point in the loading process. Be prepared for anything with high quality factory replacement parts that will have your press running like new with minimal downtime if one happens to break.