Question: Has anyone used birdshot in Snider? Spread pattern?

Hi,

I was thinking of making some birdshot shells for shooting skeet and fowl with my Cavalry Carbine and wondered if anyone has tried it.  I was thinking of #7 or #8 lead with a card wad and overshot wad but wondered if it is even worth the effort.  If you have tried it, what is a suggested powder charge FFG and do you know how the rifling might affect the spread.

Thanks,

David