Howdy!
Probably not the response you're looking for, but why not aim for 100%? Of course, that doesn't mean you need be dissatisfied with anything less.
In terms of getting the 40+ study score, it's difficult to give an estimate of what you need to get through your SACs. Different schools administer different SACs, and also mark them differently, so a 60% at my school, for example, might actually be the equivalent of a 90% at yours. In the end, raw marks in isolation don't matter that much in terms of study score calculation.
Again, I acknowledge this probably isn't the type of response you were looking for haha. But it sounds like you're doing well in Methods this year, and I'd encourage you to simply keep pushing through the content and (importantly) clarifying anything you don't understand. For example, why did you lose the marks you did on your mid-year? Doing this will give you a great change of ultimately getting that 40+ study score.
Good luck!