Russian War Machine vs. Princes of Islam

[stanc]

One of the largest U.S. military ammunition manufacturers, ATK (via Federal), is producing 6.8 SPC with a 90gr Gold Dot (or Fusion) bullet for contracts with the Saudi Arabian and Jordanian palace guards, tasked with protecting their respective royal families.

The 6.8 SPC loading is specifically a military loading for a military contract. This loading was tested by no less a personage than wound ballistician Dr. Gary Roberts. He reports that in a 16" barrel the muzzle velocity is 2604 fps. When 6.8 fans challenged his findings, claiming that his velocity readings should be much higher...

After watching the video below, I'm not surprised they questioned that 2604 fps reading.

https://www.youtube.com/watch?v=uoX68gSOfsA

Note the 16" chrono'd MV of 2850 fps, seen at 6:21-6:32 in the video.

I wonder why such a huge difference?