My FIL had an issue too, he put a rifle scope on a BP gun. Couldn't zero it. Here is why according to the gunsmith:
BP optics are set up for 100 yards, rifle are not, start at what 50 yards I guess, the reticle is different.
BP optics are manufactured for the "abuse" it would only get on a BP rifle, so in theory a standard optic would work both but not the other way. The scopes are not built to the same strengths I guess. But a rifle scope would not shoot well on a BP because a rifle scope is made for distances over 100 yards, well over. BP are made for the most reach of 125-150 because after 125 the odds of a kill shot are pretty slim so they don't need to make them reach out that far......
Now this is basically what we were told not sure if there is any truth to this.
__________________
|