This video made me curious so I created a profile on my ballistic calculator to see the numbers. I am using a Trimble Nomad running Field Firing Solutions Delta V paired with a Kestrel 4500 BT. Using the data from AXTS site for their rifle shows a 14.5" 1/8 twist barrel. The shooter in the video stated they were using a 77 grain nosler bullet. The velocity was not stated nor were the atmospheric conditions aside from the 15 MPH wind so I just used the current conditions at my location.
The fastest velocity for given load data from the nosler site is 2692 FPS. I decided to give them the benefit of the doubt and bumped the muzzle velocity up to 2800 FPS in my calculator.
My calculator shows 18.4 mils (63.27 MOA) of elevation required to hit @ 1200 yards. Here are a few pics of data from my calculator, again this is with some approximations of data on my end.
I am not saying that they didn't do this or that it can't be done and I'm not trying to start a pissing match. However, I would not be willing to bet on MYSELF recreating these shots with any sort of real consistency. A few things that would make this fairly difficult in my mind with what is shown in the video; 8 power scope, 15 MPH wind, what looks to me to be less than ideal spotting conditions.