North Georgia Ranges and Clubs?

Creekside goes out to 500y but the long range portion is only open on certain days, and Joe Harris is a great guy. he is just west of Cartersville.

Riverbend is a nice place, I've only ever shot on the 600 once, its nice but you have to shoot in relays

Gunsite Hills is great and goes out to 700 unless Chief likes you and lets you shoot 800y, kind of a hike for you, thats out in Lexington, east of Athens

Elberton Gun Club, I have no experience, but the website says 400y.

The easy answer is to find a landowner in your area and keep him stocked with booze for the use of his property for a range.