Hi all. Looking some advice and or help with a Leupold scope i bought 2nd hand. It was a 6.5x20x40 and has been boosted to 35 mag, close range adaptor etc fitted to the front. My problem is at 20 yards it is blurry ? Not mental blurry, but blurry none the less. Perfect at all other ranges, and checked with a tape and is spot on. I have another of these scopes and it's perfect at all ranges, it's just this one seems a little blurry at 20 yards Any of you scope boffins know why i would love to hear your thoughts. Can it be fixed or do i live with it and get another ?