Just as an aside, I was handed a box of factory Nosler Accubond ammo for the 9.3 last week and so out of curiosity took them to the range today to chrono them (Mondays are 'Weekly Group Therapy Sessions' for me).
On the box it says nominal MV is 2,550 fps. A 10-shot string past the chrony from my 24" barrel produced an average MV of 2,364 fps with E-S of 42 and an S-D of 15.1.
Me thinks that Nosler test barrel is a tad longer than 24" ...
I doubt their barrel is longer than 24". SAAMI companies follow SAAMI specs. Just because your barrel is the same length as the ammo companies test barrel or a powder/bullet company's load data doesn't give the same velocity you see in your barrel. So many variables will turn up different velocities. Fast barrels, slow barrels.....tight chambers, loose chambers, etc.....can cause some larger than normal velocity differences. I see/hear it all the time at work.
