Lots depends on where you position your scopes. In my case its a matter of sliding the scope as far forward as possible and hopeing its enough. I've managed to mount 50mm Mark 4s over heavy barrels with low rings, and 40 mm on sporter barrels is easy. Bear in mind that every company seems to have their own idea of what low, medium and high mean. A well stocked gunshop with staff that likes to play is invalueable.