Doc Swinson’s Single Barrel Straight Bourbon - Bottled at Cask Strength, Doc Swinson’s Single Doc Swinson’s Single Barrel Straight Bourbon Whiskey "Area to Change" is bottled at Cask Strength and is hand selected by the tastemakers. Doc Swinson’s Single Barrel Straight Rye is crafted at 96 Proof, 45.5% ABV in a 750mL bottle.