If you feel inconsistent out to 30 then that's beyond your shooting range when afield. There is nothing wrong with that, it just means that if a deer comes to 30 yards you have to be strong enough to pass the shot.
Find your comfortable range and stick to it. Don't go beyond a distance you aren't confident in.
I feel like I can shoot out to 40 yards pretty consistently but my limit in a treestand on a live animal is 35. That's where my confidence is and I won't go further.