They can both be used when discussing guns but more commonly they are used when discussing the parameters of something. Such as the scope of the project or the range of the differences in opinions. In those instances the two are often interchangeable.

Scope would be something you can see. The range of your scope can differ. You can use both interchangeably such as the target is in scope or in range. To be more specific you can say the range of my scope is 1000 yards