“Point-blank range is any distance over which a certain firearm or gun can hit a target without the need to elevate the barrel to compensate for bullet drop, i.e. the gun can be pointed horizontally at the target.[1][2]”
The law of universal gravitation means that a bullet leaving the muzzle of the barrel travels in a straight line from the muzzle until the effects of gravity. As stated above, the effect of gravity starts working on the bullet immediately.
The barrel of the firearm must be slightly elevated when fired, or the bullet would drop and come into contact with the ground very fast and relatively close to the where the projectile exits the muzzle. In reality, the rifle muzzle is elevated, and the line of sight is downward toward the target. To put it in reference, when your sights are on a target, your barrel is pointed upward. Even at close range, the muzzle is elevated, be it very slightly and when aiming, the line of sight is slightly downward.
“Point-blank range is any distance over which a certain firearm or gun can hit a target without the need to elevate the barrel to compensate for bullet drop, i.e. the gun can be pointed horizontally at the target.[1][2]”
https://www.nrawomen.com/content/dispelling-the-myth-of-bullet-rise