From what I've seen over my chronograph the factory figures are wishful thinking to say the least. A couple of examples, 25-06 ammo rated at 3150 that clocked 2700, 30-30 ammo rated at 2350 that clocked 2025. 270 ammo rated 3150 that did 2800.

Even if your ammo does chronograph at the velocity on the box that's no guarantee the trajectory will be the same. Many more variables come into play with the trajectory. Sometimes a slower load will shoot flatter than a faster load, factory ballistic coefficients are pretty wishful too. The only way to know where a rifle will shoot at a given range is to shoot it at that range.