What mag did you shoot at please?
... and a load of it is in the head. The number of times that I shoot groups and I've put say 9 out of 10 inside a very small group ( it's as if once I've seen the first couple go in the middle I'm sure the rest will ... until that last one ) and then that last 1 out of 10 I'm now thinking " This is a brilliant group ... I really don't want to mess it up with this last shot ... add the adrenaline and tension and the last 1 misses by a mile.
Amazing how often it's that last one that c0cks the group up.