I like that you have a Recoil after the shot Gary and the manner in which he raises his rifle appears as his taking careful aim. Keep his back foot (right) still as you move his left foot and slightly tilt his body to provide a shift of weight as he steps forward. Solid Steps without sliding and as Plotinus posted, without moving both feet at the same time. Experiment with the speed of his step so it appears natural and deliberate without a slow motion appearance.
One more thing to look at adjusting is after he shoots, have him lower his rifle without raising it or moving back to the default position as if it is a "rewind".
One more thing to look at adjusting is after he shoots, have him lower his rifle without raising it or moving back to the default position as if it is a "rewind".