Drag

         Drag is another factor which affects a projectile while in flight. Drag causes a loss of bullet speed as the bullet pushes its way through the atmosphere. Drag also allows gravity to have a greater effect because the bullet is in the air for a longer period of time. Other things that may influence drag is the ambient air density, or the measure of humidity, air pressure, and temperature.

             As temperature increases, there are less air particles for the projectile to impact while in flight. Therefore, the hotter it is, the further your shot will travel. Also, as you increase in altitude, the thinner the air becomes, causing the same effect and ultimately causing a further flight period.

             Humidity is the measure of how much water vapor is in our airs atmosphere in a given area. Most people think that wet, sticky air will cause the bullet to travel less than dry air, but they are wrong. Water vapor has a density of .8 grams per liter while dry air has a density of 1.225 grams per liter. The less dense the air is, the less drag there will be. Therefore the more humid it is outside, the further the bullet will travel.