The main reason I got out of using shotguns for deer hunting is the cost of saboted slugs. Pistol ammo is more cost effective which means you get more practice at the range. Reloading offers a variety of options with ammo.

A magnum pistol round fired from a rifle is surprisingly effective in the 100 yard range. I have not seen any disadvantages to the terminal ballistics on whitetail deer compared to shotguns. On the other hand my Marlin or Ruger pistol caliber carbines do have advantages in trajectory compared to shotguns.

Indiana is most likely going to expand legal calibers choices next year so I would wait till you purchase a firearm. A .410 or .44 mag is going to be inferior to a .243 if made legal. If you have to buy now get a Handi rifle in .44 mag they are economical.