Hey the only thing you can do is wait it out and hope he turns broadside cause honestly another 10 to 15 yards beyond your comfort with a rifle you should be good if you are grouping 1" at 150 yards. Or try moveing up the tree line and sit on the ground, but just don't sit right on top of his trail. Also make sure the wind is good and you don't leave to much human scent around. Goodluck and hope you put him down.