It might be set with staking or soldering. A little item would be that the pin which retains the firing pin spring cap tended to work unfastened, and had to be tapped back again in place as 1 observed it venture with the rear in the bolt. Winchester replaced that https://highimpactrounds.com/product/winchester-aa-xtra-lite-12-ga-2-75-in-1-oz-8-lead-1180-fps-25-rd-box/