A screw-in choke tube of various constrictions with electrically discharge machined (EDM) ports and smooth parallel section. The porting acts as a muzzle brake and helps strip the shot cup from the shot load. A ported choke tube will keep the wadding and shot cup from interfering with the shot string as it leaves the muzzle. Permanently marked with both bore diameter, constriction and constructed from 174 PHA stainless steel, heat treated and polished.