Hello Ray,
There's indeed a problem with the pose.
The guy feels awkward and uncomfortable like if he's banding all his mucles to stay in position and would be falling over when nobody's looking.
The main problem is the pose. You chose to portrait a man leaning on his rifle. That means that would shift his body so that instead of standing on his two feet, his weight would now rest on a TRIPOD (the two feet and the rifle butt).
In the final position, if we draw a vertical line starting from the head (green line), it would hit the ground in the dead centre of a triangle composed by the two feet and the rifle butt. Think camera tripod. The head is the camera and the tripod legs (yellow lines) are the man's legs and the rifle butt.
Now that we've pin-pointed the problem, how to correct it?
1– The rifle should be aligned on the yellow line (butt moving further away from the body and muzzle resting under the chin.
2– As a result, the arms will move closer to the body.
3– The legs should not be bent at the knees. Quite the reverse as the hips should be thrusting forward to counteract the crouching torso.
This is just the start. You will find as you make the corrections that other parts of the body will move as well.
The complexity (and beauty) of the human machine is that when one thing is moving, everything else moves along. :lol:
HTH
Quang