From a quick search it seems both a normal gallon and a wine gallon are measured at 231 cubic cm of liquid, so they're the same. There is a proof gallon which o

From a quick search it seems both a normal gallon and a wine gallon are measured at 231 cubic cm of liquid, so they're the same. There is a proof gallon which only counts the ethanol content of the liquid towards the gallon, so a 100 proof alcohol would require 2 gallons of liquid to equal 1 proof gallon of liquor.