How much alcohol for 300 people?

It depends on the occasion, If everyone were to have only one standard drink per person or one 50 ml shot of 80 proof liquor 40% alcohol by volume. Then one 750 ml bottle would serve 15 people. Because 50ml x 15 = 750ml. If the motive is to have enough for everyone to get buzzed, then double or triple the math. I weighed up to 220 pounds in the past and now weigh 165, & I must say 4 to 6 shots of whiskey in less than a 6 hour period knocks me out cold. So 16.6 750ml bottles of let's say Canadian whiskey would give 250 people one shot to drink each.