I use the same loads, ()77 SMKs at 2&300 yards, 80 SMKs at 600 & 1000) in my White Oak Service Rifle.
Mine has 1/2 MOA Clicks. I zero at 200, come up 6-8 clicks to 300, and I use 26-28 at 600. (Depending on weather conditions).
For 1000 yards I use my 600 zero and turn my front sight 4 full revolutions down.
For 100 yard practice on the NRA 100 yard reduced targets I use my 200 yard zero and turn the front sight UP one full revolution.
Again I have 1/2 min clicks, if your's is 1/4 you'll double those numbers.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071