RE: 12ga. or 30-30
If your 12 ga shoots great out to 75 yards use it for your brush gun. That 1oz slug is 3 times heavier than that 30-30 bullet.
Shot many a deer with my 870 with a smoothbore and 1oz. rem sluggers. Now I have a rifled barrel on it and it is more accurate at longer ranges and with a sabot round. I like fed premium rounds.
I like to aim high on the shoulder on broadside shots and it knocks them flat. Too many other hunters out during gun season, I dont want the deer to run off.
On the same exact hit a 12 ga slug will stop a deer much faster than a hit from a 30-30. Or any other deer rifle caliber at that range.