In poor light from the fence line I can see only silhouettes much beyond 30 yards. If I sit quiet as they come by I can pop one or two. The .410 is a single-shot bolt action. By the time I reload they are gone. If I miss on the first pull, I’ve got no chance at a second.
dung.
Another option I havn’t seen anyone here bring up is a thompson contender. I’m pretty sure you can get barrels for blackpowder for it. I’m not sure about shotgun barrels though. But they are only single shot. If you don’t like single shot guns it may not be to your liking.