What you guys are talking about is called "Acceptable Accuracy." That is defined as the level of accuracy that will do the intended job of the gun you are shooting.
You don't need one hole groups to shoot pigs at 30 yards. Any hit with a Slug will probably take out the pig. I saw a pic of a Russian Boar that was shot by a guy's Wife with a O/U Shotgun. This thing was huge maybe 6-800 lbs and she nailed it right thru the shoulder and it dropped. DRT! Probably a Brenneke Slug or maybe a Lightfield as I don't think they were reloaders. But my point is that the round was powerful enough to take that critter down with that shot placement, and teh fact that the gun was a 3-4" gun @ 50 yards didn't make one Iota of difference to the Boar!
I look for Acceptable Accuracy or Usable Accuracy from all my guns.
I shot this one with my A5 and my Non toxic Slugs at 50 yards with open sights on a Hasting Rifled barrel. I think this is good enough for whatever I want to shoot with that gun.
The second group was shot offhand at 50 yards with my 20" M500 with Rifle Sights and Federal Low Recoil Slugs. I think that is good enough for anything with that gun.
I was holding my Mouth a little to the left on that group.
Randy