1 boneless beef rump roast (about 4 pounds)
2 cups barbecue sauce
1 cup root beer
Dash of salt and pepper to taste
16 sandwich buns
Place beef in a crock pot. In a small bowl, mix 1-1/2 cups of the barbecue sauce and the root beer; pour over the beef. Cover and cook on low for 10 to 12 hours.
About 20 minutes before serving, remove beef from crock pot; place on a large plate. Pour juices from crock pot into a 12-inch skillet.
Cook over medium-high heat about 15 minutes, stirring occasionally, until juices are thickened and reduced to about 3 cups. Meanwhile, shred beef with two forks; return to crock pot.
Stir remaining 1/2 cup barbecue sauce into reduced juices in skillet; pour over shredded beef in crock pot. Stir in salt and pepper to taste.
Spoon about 1/2 cup of the beef mixture onto each sandwich and serve while hot.