I only know what I've read about long range but here is my advice.
If you have an Android phone download Strelok, a free ballistic program.
It says you will need 54 MOA to get to 1000yds with a 123g .4BC bullet at 2400FPS.
Your scope has 75 MOA adjustment so 37 up and 37 down.
With a 20 MOA base you can get to 37 + 20 = 57 MOA so it will just make it.
You would have some extra by using one of the lower dots on your mildot scope.
I did find a course in Lewistown, PA, close enough for me to drive.
I think LRRPF52 teaches a similar course. I am sure he will chime in.
If you have an Android phone download Strelok, a free ballistic program.
It says you will need 54 MOA to get to 1000yds with a 123g .4BC bullet at 2400FPS.
Your scope has 75 MOA adjustment so 37 up and 37 down.
With a 20 MOA base you can get to 37 + 20 = 57 MOA so it will just make it.
You would have some extra by using one of the lower dots on your mildot scope.
I did find a course in Lewistown, PA, close enough for me to drive.
I think LRRPF52 teaches a similar course. I am sure he will chime in.