If you expect to fire at predators from a tripod or a forend-mounted bipod, practice with that support, not from sandbags on a bench. A taut sling affects forend pressure and barrel vibration during bullet travel through the bore. (A sling often tugs my shots 1 to 3 inches to 7 o’clock at 100 yards.) Eye placement relative to the sight can change with position, too. Your head tips forward in the prone position, nearer the scope. Pulling back to dodge the eyepiece in recoil alters cheek-to-comb pressure and other aspects of your position.  Whatever low position you’re blessed — or compelled — to use, check it as time allows. Your rifle will point somewhere. Make sure its natural point of aim is to the target. Close your eyes for two breaths and consciously relax; then look at the target. If the sight is elsewhere, adjust your position from the earth up. Forcing the rifle induces tension you can’t maintain when the trigger breaks.