Hunter's Run in Port Allen, but that is a shotgun club; the rifle and pistol "ranges" are very crude and go no farther than 25 yards.
According to Packing.org it's open 2p-6p on the 2nd and 4th Thursdays of the month.Thanks, The Ascension Sheriff's Office range in Gonzales is closed today but I'll call them to see when they are open. I'll post up here when I find out.