In a small bowl, stir together sour cream, horseradish, chives, and lemon juice. Spoon half of the sour cream mixture in one side of a 4-cup shallow serving bowl. Spoon half of the cocktail sauce into the bowl next to the sour cream mixture. Spoon the rest of the sour cream mixture over the sour cream mixture in the bowl and the rest of the cocktail sauce over the cocktail sauce. If desired, cover and chill dip mixture for up to 4 hours before serving.

To serve, place the bowl containing the dip mixture on a platter. Rinse shrimp; pat dry with paper towels. Arrange shrimp around the bowl. Garnish with chives and/or lemon wedges. Makes 30 servings.