Well, with all the former SEALS, Marines, etc. on FR, we have to find someone to settle this thing ... clicks, inches, or feet! Surely one of us went thru Scout/Sniper school in the Marines, and can settle this once and for all.
Which can be either 1/4 M.O.A., 1/2 M.O.A., 1 M.O.A., ect.
Of course 1/4 M.O.A. is the finest setting.
Also the scope would be calibrated for the caliber of bullet that is being shot, in this case .308/7.62mm and in meters or yard.
M.O.A. can be describe as 1 inch wide at 100 yards, 2 inch wide at 200 yards and so forth.
Therefore 1/4 M.O.A. would be 1/4 inch guoup at 100 yards.
I realize this is on the simple side, but I'm a simple guy.
Hope it helps.
Talk with any varmint hunter 800 yards is very do able. There are people who shot out past a mile for the fun of it.