Had a cover come through the post today, fitted to my Hawke, also found it a little snug but on reflection I suppose it has to be to stop it moving.
Anyway, results. I agree with the above review, found it to really speed up aiming & works best once you stop trying to use it - it seems to come naturally to line everything up.
It has definately improved accuracy as well, groups are much tighter at ranges from 20 - 25 yds & at various heights. 20 quid well spent