The pass mark for both SWGS and BWS was 317 this year which the SWGS website equates to 75%.
However the individual scores for each test really didn't seem to correlate at all to how my daughter scored on the NFER papers she did just before the exams (and both schools use the same test). She also said that the tests were generally harder than the NFER papers.
I know of one child that scored well below 300 and got through on HT review.
[Edit - Hurray! The Wilts section is alive and kicking! Well today anyway!