Eventually, a bullet sheds enough velocity to become unstable. Then, unless weather conditions are ideal, meaning no wind, the bullet will begin to fly erratically and tumble end over end. At that point (distance) Marksmanship ends. Most of the US Service Rifles from the 1903 Springfield to today's M16-A4 will get a projectile to 1000 yards nose-on. However, in the case of the M16 and its commercial equivalents, special ammunition and match conditioning of the rifle is needed to persuade bullets to go the distance. The former US Service Rifle, the M14, also needs match conditioning and special long range ammunition for competitive results at 1000 yards. The bottom line is Long Range Service Rife Competition requires shooters to muster everything there is to know about good shooting to win at it. The thing that separates the winners from others is knowing when position has synced with natural point of aim, much as the Princess could feel a pea under a stack of mattresses.