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 just one noticed it undertaking in the rear of the bolt. Winchester replaced that https://highimpactrounds.com/product/winchester-super-x-12-ga-2-75in-1-oz-8-lead-1290-fps-25-rd-box/