Arena Training Facility in Blakely GA isn’t open to the public, but they hold regular events there that anyone can attend. They have numerous ranges (it’s a 3800 acre facility) and they hold open range days on their 2500yd range once in a while. They have almost 30 steel targets from 100yds out past 2000yds. I host shoots there a few times a year, got one coming up Dec 9-10 if you’re interested.
Not in Georgia, but not far across the border, Elk River Training Center in Pelham TN has steel from 100-1,000yds. I teach there quite often. If you’re not attending a hosted class, you’ll need a membership, but it’s cheap.