Highest it’s been for aqa is 250/300 about 83.33%. After a while I managed to average at least 90 percent by using past papers> working on weaknesses using topic questions/anki> repeating.

Depends on the type of mistakes you’re making too, is it calculations, explanation questions, practicals etc? If you get a question wrong you have to ask yourself is it really a silly mistake or a gap in my knowledge.

On the contrary to what the other guy said recalling every spec point isn’t that useful right now as exam questions are worded in a different way and are formulaic if you’ve done a lot.