It may be set with staking or soldering. A small product would be that the pin which retains the firing pin spring cap tended to operate free, and had to be tapped again in place as one particular saw it job from your rear of the bolt. Winchester replaced that https://highimpactrounds.com/product/winchester-super-x-20-ga-2-75-in-8-7-8-oz-1210-fps-25-rd-box/