AR15 ring height

This isn't a bike topic but since I usually ride my softtail to the range, here it goes. Does anyone know if you need a riser with high profile rings on the picitiny rail of a flat top of an ar in order to mount a scope?
In other words, will high rings give me access to the charging handle? Or will I need a riser too?

Depends how close you mount your scope to the charging handle (adjustable stock?). The simpler answer would be that a riser would that eliminate worry...but I don't use one. I do expect to get look-thru rings some time in the future, though, which would eliminate any obstruction problem and give you better close-quarter-combat sighting.

Also, there are charging handles for sale that overcome this problem (bcidefense.com)

Remember that the scope height will seriously effect your distance shooting.

And next time, this topic really would better in "Pull up a chair."