It might be set with staking or soldering. A little product is that the pin which retains the firing pin spring cap tended to work free, and needed to be tapped again in place as one particular observed it venture with the rear of the bolt. Winchester replaced that pin https://highimpactrounds.com/product/winchester-xpert-20-ga-2-75in-6-3-4-oz-1325-fps-game-load-25-rd-box/