Bounder Primstone is a Bounder who is found inside the Brockenborings Watch Office in the Shire. He is the kind of Bounder who seems to know his role as a watcher of the people of Brockenborings, not the kind of bounder that "protects" the local tavern. Thus you will indeed find him on duty in the Watch Office.
He is friendly to a man that he calls Hunter, who can be found north-east of Brockenborings.
In the last part of the Shire Epic tale, in Shire Epic Prologue: Instance: Beneath the Greenfields, Primstone bravely but foolishly assaults the goblin's lair, carrying the club of the Bullroarer in attempt to scare the Goblins away from the Shire.