The only truly stupid question, is an un-asked one. All a range finder does is.....find the range. it reads the distance between the rangefinder and the target it is aimed at. How you reach across that distance, is entirely up to you.
Now, that being said, some high dollar scopes, include a rangefinder. And that scope, may or may not be able to take the shock of a shotgun VS a rifle.
So, if you are going that route, then make sure the scope is rated for the weapon it is to be used on. If it is a hand held rangefinder, it can be used with any weapon. It is only there, to let YOU know, what distance you need to adjust for.
Hope that helped.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.