I recently bought a Brod and Taylor baking shell, weighs 500g. I use that on a Brod and Taylor steel sheet. Times long gone, I used a very heavy cast iron Dutch oven.
I had to heat the dutch oven until it was extremely hot, the hottest my oven would get. That was accompanied by all the risks that went with the weight and the heat, the dutch oven had to be handled out of the oven before dropping the dough into it, then the dough had to be slashed with a lame, a device holding a very sharp razer blade
Real sourdough is what I grew up with, especially loving the black bread from Coopers in Liverpool
You can easily make a sd loaf in a loaf tin, putting another loaf tin on top to keep the steam in. I only have a basic fan oven, no good for sd baking, hence I need the baking shell or a dutch oven