Originally Posted by Yorkshiretea
Don't worry about your English Tasik. What you need is a Shark Fin or Offset Wheel, these will give you bigger gaps as they are both usually about 180mm. I think you may find 200mm a bit too big as well as catching a lot of wind.
The gaps between 40yds and 50yds should be fine with 150mm it's always been 50yds to 55yds that's the problem.
A more expensive way to fix this is to buy a Sightron and enjoy the 8mm gap between 50yds and 55yds
But do you have a problem if someone puts a target out at 60 yards by mistake? Is the max readable distance 57 yards?