What kind of primer pocket swager do you have , that goes into the mouth of a case ? Were you thinking Flash hole uniformer instead ?
The RCBS primer pocket swager comes with two rods small and large. These go through the mouth of the case and push the case down onto the swager which comes in small and large.
The smaller one used for cases like 223 or 6mm Rem and the like, you have to make sure you get the rod into the case mouth before putting much pressure on the press. If not you can deform the case mouth. Not a real problem but does slow down the process when you’re working on hundreds of 223 cases.
"The difference between stupidity and genius is that genius has its limits" Albert Einstine