Factors include the angle at which it is fired, the speed of the projectile, its shape (ballistic coefficient) the air pressure and humidity.

Trajectory of a bullet in flight is governed by a combination of the initial speed, the ballistic coefficient of the bullet, the angle at which it is fired, and external factors such as air temperature, humidity, wind speed, and air pressure. Ballistic coefficient is a value assigned based on the bullet shape and its length to diameter. A bullet with a higher ballistic coefficency will retain energy (speed) better than one with a low BC. There are several computer programs that can be used in the speed and BC (the major factors) are known.

Generally they don't. Lighter bullets generally have a worse ballistic coefficient as compared to heavier bullets of the same caliber.

No such caliber. Sorry. If you man the Lapua .338 Magnum, drop will depend on the ballistic coefficient of the bullet being used, it speed, etc.

Good question. Since the answer depends on the barrel elevation angle, bullet shape, weight, and ballistic coefficient, the best way to answer this is to have you do an online search on the words, "ballistic calculator". You will find several sites that let you enter those variables and will give you the answer you seek.