You should chunk your MOA calculator and get a new one.
Sorry, I didn’t use a calculator. Calculator says at 600 yards, moa ia 6.283”. That is a radius. Means the diameter is 12.566”. Minute of angle accuracy at that distance will place your shot anywhere plus minus 6.283” from where you were aiming.
This does not take into account other variables such as windage, drop, your heartbeat and breathing, your inability to hold perfectly still, motion and speed of the animal, etc.