As I recall, Ft. Knox is now a closed base, which means unless you have an official reason to be there, you're likely not getting on. Kind of sad, when I was younger I used to go to French range on base with my pals. The longest range I know of around my area (Louisville) is Knob Creek, but just outside of Lexington there is a place called the Bluegrass Sportsmen's League, Inc. (http://www.bgslinc.com/
). Looks like they only have up to 300 yd. ranges though. You also have to be a member if my reading was correct. It looks like a very nice facility though.