A scope with a small size objective lens has less error than a scope with a large one.
Try the new mtc connect with a 24mm objective, very little error.
People say the sr6 has little error. Thats not really correct, it has lots but the ret changes colour if your heads not in the correct place, which tells you to line yourself up again.
I had an old Hawke varmint which did much the same. Sr6 glass was way better though.