It can be fastened with staking or soldering. A little item would be that the pin which retains the firing pin spring cap tended to operate loose, and needed to be tapped again in place as 1 noticed it challenge from your rear with the bolt. Winchester replaced that pin https://highimpactrounds.com/product/winchester-aa-12-ga-2-75in-1-1-8-oz-8-lead-1145-fps-25-rd-box/