Place Roast In A 5-Qt. Slow Cooker. Combine The Salad Dressing Mix And Water; Pour Over Roast. Cover And Cook On Low For 8 Hours Or Until Meat Is Tender. Remove Meat; Shred With A Fork And Return To Slow Cooker. Add Pepper Rings; Heat Through. Spoon 1/2 Cup Meat Mixture Onto Each Bun.