That's really not too bad. I've sure seen a lot worse.

Have you zeroed the rifle from a bench prior to this?

You've got a base line to beat for comparison when you practice.

If you've go one of those called a flier for a known reason, flinch ect. Then you know ONE thing in the mix to over come with practice.

May be there is a little room to practice with the hasty and get it pulled in tighter. May be it can help. The other option is to set it up like a true shooting sling with it hooked in front and the loop adjusted around your support arm. Get things locked up before the shot to take as much muscle tension as possible out of the equation.