I own a Mossberg bolt action with the C-lect choke system. When it first came out it was novel, because it allowed a person to change the choke in the field, which could be useful if you hunted multiple types of game on the same trip or on the same day. You could literally carry #7 shot or 00 buckshot on a hunting trip and harvest squirrel, birds or deer (which have overlapping seasons in some areas, such as the upper Adirondacks of NYS).

I'll also argue that bolt action slug guns (such as Savage and H&R) are the most accurate slug guns on the market and also some of the most expensive shotguns made for a single purpose. Compared with a Mossberg or Remington pump (that have a choke tube system or different barrels), these slugs guns with fixed rifled barrels will cost you $400-1000...