There are no set grade boundaries for the specimen papers, practice papers, or end of topic tests that OCR produce.
The ideal assessments would have the E boundary at about 40% raw marks and the A boundary at 80%. This was the aim with the legacy assessments, the new assessments and the specimen and practice materials – there has been no change to this for many years.
Historically it has proved challenging to hit the aspiration of 80% raw marks for an A. The final boundary tends to be lower than this. This is also true of the E boundary.
Grade boundaries are only set for a 'real' exam when it has been taken by the full national cohort of students. The 'awarding' process sets grade boundaries based on actual student performance and the expected outcomes of students based on GCSE performance. This cannot happen with specimen or practice material.