Where I hunted in upstate NY and northern Vermont 50 yards was a LONG shot. Most of the deer I killed were with a Ruger .45. I think that some form of rudimentary sights like the ones fitted long ago on my 10 bore Rem. would still be in order. Since my Valmet "Lion" has a rib, I might attach some clamp-on slug sights to it and use those.
Yogi, thanks for the info and load data. I have no doubt that a solid round ball from any shotgun guage would be effective on a blacktail at the feasible ranges. For piggies, I'd use the harder ball as you suggest (and keep a deer slug or buckshot in the other barrel for follow-up....).