There was a bit of "blue sky" with the quoted velocities in the past. In fact, the only way to go over 2100 was with a 26" barrel or so. I believe the velocities of old were achieved with pressure barrels only. Also, the Winchester people loaded the original rounds with ball powder and severely compressed them when seating the bullet and gluing the bullet in place. The factories realized that chronographing the actual velocites out of an actual rifle gave a more practical velocity. They also downloaded the round with less powder for a while. With today's powders and combination of bullets, you can safely reach 2150 w/o overly compressing the powder and do so w/o skyrocketing pressures.