Please take a closer look at the first video, on 05 second, he aims at a person, and then his gun moves horizontally to the left, then stops and then returns it back.. the same happens on a second time code on 0:25 second. I was looking at it in a slow motion at a speed of 0,25, if you'll take a look perhaps you'll see that at the both timecodes, the gun moves exactly the same way and to the same distance horizontally. Usually.. because of the hitback the gun moves up and down.. but on a first video he begins to shoot, then his aim goes to the left.. returns on the same position and then starts moving up and down