Possible Clues:

• There's something about the wine that may go off
• Colt sound
• By the sound of it, will this go off about the drink
• The matter of what's in 20 down may make it go bang
• Present oneself
• News item - sound of gun
• About one drink, by the sound of it
• Sharp noise; rumour
• What about a drink? Bang on!
• There's something about drink that 17 down may cause