This is what we found on Wikipedia regarding the Sabrage:

Sabrage is a ceremonial technique for opening a sparkling wine bottle, typically Champagne, by striking it with a sword or similar implement. The blade is placed towards the base of the bottle and thrust along the length of the neck, where force of the striking point hitting the lip breaks the glass to separate the collar from the neck of the bottle. The cork and collar remain together after separating from the neck. The act can be performed using a real saber or other bladed weapon, but is today most often done using a specialized Champagne sword. Derived techniques can employ almost any flat object as desired. Despite the military origins and stylings of the act, a sharpened edge would be detrimental to the striking effect; Champagne swords are left unsharpened and therefore do not qualify as true weapons, while real sabers must be reversed such that the collar is struck by the dull side of the blade.